Threaded ResourceLoader crash on startup (GDScript)

### Tested versions Reproducible on v4.8 current 3defa246 ### Issue description Once the project reaches a critical mass of number of GDScript files present, trying to use threaded loading with intermittently fails and crashes in the GDScript loader. This is possibly related to #120827 which i previously encountered in the same project, but this is a crash instead of a deadlock and occurs without any preload()s present in the project. Either it results in a crash (stacktrace below) <details> <summary>Stack trace from debug build.</summary> ``` SCRIPT ERROR: Parse Error: Could not resolve inheritance for class "<main>". at: GDScript::reload (res://scene/prop/tool/flashlight.tscn::GDScript_ouvoj:1) [1] 7f7f6303e6f0 (main+3e6f0) - end at uspoof_impl.cpp:0 [2] 556a74966296 (godot.linuxbsd.editor.x86_64+47a7296) - CowData<char32_t>::size() const at /home/chris/src/godot/core/templates/cowdata.h:176 [3] 556a7488acf8 (godot.linuxbsd.editor.x86_64+46cbcf8) - GDScriptAnalyzer::resolve_class_inheritance(GDScriptParser::ClassNode*, GDScriptParser::Node const*) at /home/chris/src/godot/modules/gdscript/gdscript_analyzer.cpp:350 [4] 556a748a775a (godot.linuxbsd.editor.x86_64+46e875a) - GDScriptAnalyzer::resolve_class_inheritance(GDScriptParser::ClassNode*, bool) at /home/chris/src/godot/modules/gdscript/gdscript_analyzer.cpp:652 [5] 556a748ee0d2 (godot.linuxbsd.editor.x86_64+472f0d2) - GDScriptParserRef::raise_status(GDScriptParserRef::Status) at /home/chris/src/godot/modules/gdscript/gdscript_cache.cpp:97 (discriminator 2) [6] 556a7488c13d (godot.linuxbsd.editor.x86_64+46cd13d) - GDScriptAnalyzer::resolve_class_inheritance(GDScriptParser::ClassNode*, GDScriptParser::Node const*) at /home/chris/src/godot/modules/gdscript/gdscript_analyzer.cpp:483 (discriminator 1) [7] 556a7488dd08 (godot.linuxbsd.editor.x86_64+46ced08) - GDScriptAnalyzer::resolve_class_inheritance(GDScriptParser::ClassNode*, bool) at /home/chris/src/godot/modules/gdscript/gdscript_analyzer.cpp:652 [8] 556a748b7ff4 (godot.linuxbsd.editor.x86_64+46f8ff4) - GDScriptAnalyzer::resolve_inheritance() at /home/chris/src/godot/modules/gdscript/gdscript_analyzer.cpp:6704 [9] 556a7486257c (godot.linuxbsd.editor.x86_64+46a357c) - GDScript::reload(bool) (.part.0) at /home/chris/src/godot/modules/gdscript/gdscript.cpp:844 [10] 556a7486365f (godot.linuxbsd.editor.x86_64+46a465f) - GDScript::_set(StringName const&, Variant const&) at /home/chris/src/godot/modules/gdscript/gdscript.cpp:1037 [11] 556a79d0eff2 (godot.linuxbsd.editor.x86_64+9b4fff2) - Object::set(StringName const&, Variant const&, bool*) at /home/chris/src/godot/core/object/object.cpp:294 [12] 556a7856738f (godot.linuxbsd.editor.x86_64+83a838f) - StringName::~StringName() at /home/chris/src/godot/core/string/string_name.h:191 (discriminator 1) [13] 556a78569686 (godot.linuxbsd.editor.x86_64+83aa686) - ResourceFormatLoaderText::load(String const&, String const&, Error*, bool, float*, ResourceLoaderConstants::CacheMode) at /home/chris/src/godot/scene/resources/resource_format_text.cpp:1467 (discriminator 1) [14] 556a79895354 (godot.linuxbsd.editor.x86_64+96d6354) - ResourceLoader::_load(String const&, String const&, String const&, ResourceLoaderConstants::CacheMode, Error*, bool, float*) at /home/chris/src/godot/core/io/resource_loader.cpp:289 (discriminator 1) [15] 556a79896059 (godot.linuxbsd.editor.x86_64+96d7059) - CowData<char32_t>::~CowData() at /home/chris/src/godot/core/templates/cowdata.h:225 [16] 556a79d89093 (godot.linuxbsd.editor.x86_64+9bca093) - __gthread_mutex_lock(pthread_mutex_t*) at /usr/include/c++/16/x86_64-pc-linux-gnu/bits/gthr-default.h:795 [17] 556a79d89863 (godot.linuxbsd.editor.x86_64+9bca863) - WorkerThreadPool::_wait_collaboratively(WorkerThreadPool::ThreadData*, WorkerThreadPool::Task*) at /home/chris/src/godot/core/object/worker_thread_pool.cpp:568 [18] 556a79d8aa22 (godot.linuxbsd.editor.x86_64+9bcba22) - __gthread_mutex_lock(pthread_mutex_t*) at /usr/include/c++/16/x86_64-pc-linux-gnu/bits/gthr-default.h:795 [19] 556a78f08c3e (godot.linuxbsd.editor.x86_64+8d49c3e) - RendererSceneRenderImplementation::RenderForwardClustered::mesh_generate_pipelines(RID, bool) at /home/chris/src/godot/servers/rendering/renderer_rd/forward_clustered/render_forward_clustered.cpp:5032 (discriminator 7) [20] 556a78d25ecc (godot.linuxbsd.editor.x86_64+8b66ecc) - RenderingServerDefault::mesh_create_from_surfaces(Vector<RenderingServerTypes::SurfaceData> const&, int) at /home/chris/src/godot/servers/rendering/rendering_server_default.h:386 [21] 556a784a3bcb (godot.linuxbsd.editor.x86_64+82e4bcb) - ArrayMesh::_set_surfaces(Array const&) at /home/chris/src/godot/scene/resources/mesh.cpp:1690 (discriminator 2) [22] 556a756168df (godot.linuxbsd.editor.x86_64+54578df) - void call_with_variant_args_helper<__UnexistingClass, Array const&, 0ul>(__UnexistingClass*, void (__UnexistingClass::*)(Array const&), Variant const**, Callable::CallError&, IndexSequence<0ul>) at /home/chris/src/godot/core/variant/binder_common.h:58 (discriminator 5) [23] 556a756169eb (godot.linuxbsd.editor.x86_64+54579eb) - Variant::'unnamed0'::() at /home/chris/src/godot/core/variant/variant.h:255 [24] 556a79ce7d5d (godot.linuxbsd.editor.x86_64+9b28d5d) - Variant::~Variant() at /home/chris/src/godot/core/variant/variant.h:879 [25] 556a79d0ef66 (godot.linuxbsd.editor.x86_64+9b4ff66) - Object::set(StringName const&, Variant const&, bool*) at /home/chris/src/godot/core/object/object.cpp:257 (discriminator 1) [26] 556a79872082 (godot.linuxbsd.editor.x86_64+96b3082) - Variant::~Variant() at /home/chris/src/godot/core/variant/variant.h:879 [27] 556a798755cb (godot.linuxbsd.editor.x86_64+96b65cb) - ResourceFormatLoaderBinary::load(String const&, String const&, Error*, bool, float*, ResourceLoaderConstants::CacheMode) at /home/chris/src/godot/core/io/resource_format_binary.cpp:1182 (discriminator 1) [28] 556a79895354 (godot.linuxbsd.editor.x86_64+96d6354) - ResourceLoader::_load(String const&, String const&, String const&, ResourceLoaderConstants::CacheMode, Error*, bool, float*) at /home/chris/src/godot/core/io/resource_loader.cpp:289 (discriminator 1) [29] 556a7988278d (godot.linuxbsd.editor.x86_64+96c378d) - Ref<Resource>::is_valid() const at /home/chris/src/godot/core/object/ref_counted.h:196 [30] 556a7988288c (godot.linuxbsd.editor.x86_64+96c388c) - ResourceFormatImporter::load(String const&, String const&, Error*, bool, float*, ResourceLoaderConstants::CacheMode) at /home/chris/src/godot/core/io/resource_importer.cpp:169 (discriminator 1) [31] 556a79895354 (godot.linuxbsd.editor.x86_64+96d6354) - ResourceLoader::_load(String const&, String const&, String const&, ResourceLoaderConstants::CacheMode, Error*, bool, float*) at /home/chris/src/godot/core/io/resource_loader.cpp:289 (discriminator 1) [32] 556a79896059 (godot.linuxbsd.editor.x86_64+96d7059) - CowData<char32_t>::~CowData() at /home/chris/src/godot/core/templates/cowdata.h:225 [33] 556a79d89093 (godot.linuxbsd.editor.x86_64+9bca093) - __gthread_mutex_lock(pthread_mutex_t*) at /usr/include/c++/16/x86_64-pc-linux-gnu/bits/gthr-default.h:795 [34] 556a79d8958c (godot.linuxbsd.editor.x86_64+9bca58c) - MutexLock<MutexImpl<std::mutex>>::MutexLock(MutexImpl<std::mutex> const&) at /home/chris/src/godot/core/os/mutex.h:77 [35] 556a79682055 (godot.linuxbsd.editor.x86_64+94c3055) - Thread::callback(unsigned long, Thread::Settings const&, void (*)(void*), void*) at /home/chris/src/godot/core/os/thread.cpp:64 [36] 556a7a1846e9 (godot.linuxbsd.editor.x86_64+9fc56e9) - execute_native_thread_routine at uspoof_impl.cpp:0 [37] 7f7f63097f42 (main+97f42) - end at uspoof_impl.cpp:0 [38] 7f7f6311efac (main+11efac) - end at uspoof_impl.cpp:0 -- END OF C++ BACKTRACE -- ================================================================ ``` </details> OR it triggers several `GDScript::reload: Parse Error: could not resolve class "..."` errors that reference one of the several more commonly inherited-from GDScript classes used multiple places in the scene (but not always the same one) and a random subset of those will not load at all, but the scene still opens just minus those scripts. ### Steps to reproduce Create a sufficiently complex godot project that includes several interdependent resources and script files, including some scripts that inherit from a shared base class, put them all in a scene, and load the scene using `ResourceLoader.load_threaded_request()` ### Minimal Reproduction project (MRP) Due to the nature of it I can't really provide an MRP, and haven't had much luck recreating the issue with a debugger attached. I can somehow provide a copy of the project in question if any maintainers are interested, but it's too large to upload to a github issue (and the issue only seems to happen with the larger project).