clangd-tidy is sometimes failing with errors like `'clang/Basic/RegularKeywordAttrInfo.inc' file not found`

Example PR: https://github.com/carbon-language/carbon-lang/pull/7062 Failing job: https://github.com/carbon-language/carbon-lang/actions/runs/24464568652/job/71487917608?pr=7062 Start of output: ``` toolchain/check/call.cpp:7:10: Error: In included file: 'clang/Basic/DiagnosticGroups.inc' file not found [pp_file_not_found] 5 | // DO NOT MERGE. 6 | 7 | #include "toolchain/check/call.h" | ^~~~~~~~~~~~~~~~~~~~~~~~ 8 | 9 | #include <optional> toolchain/check/call.cpp:17:10: Note: 17 | #include "toolchain/check/deduce.h" | ^ ```