[Bug] Heap command does not work on 32bit ARM architecture

### GEF+GDB version ```shell GEF 2025.01 SHA256(/opt/pf/data/home/papgft/gef.py): 1b15645a74bd71170093754d0322f4666cb30a73bc95b78daea7c654e1053487 GDB: 13.1 GDB-Python: 3.11 ``` ### Operating System Custom debian bookworm, libc 2.36 ### Describe the issue you encountered I am debugging a heap issue on a custom debian based linux on an embedded system using a **32 bit** ARMv7 processor. GEF does not correctly parse the main arena, because it assumes padding fields to be present which are actually not. Specifically, the field "("UNUSED_c", ctypes.c_uint32), # padding to align to 0x10" in function "malloc_state_t()" is not present in my 32 bit architecture. Removing this line makes GEF work as expected. ### Do you read the docs and look at previously closed issues/PRs for similar cases? No ### Architecture impacted - [ ] X86 - [ ] X64 - [x] ARM - [ ] ARM64 - [ ] MIPS - [ ] MIPS64 - [ ] PPC - [ ] PPC64 - [ ] RISCV ### Describe your issue. Without a proper reproduction step-by-step, your issue will be ignored. Start GEF on a 32 bit ARM architecture and issue "heap arenas" command. Current output on my system (next pointer is invalid): Arena(base=0xb66157a4, top=0x543b98, last_remainder=0x543af8, next=0x0, mem=421888, mempeak=3059171121) Output after removing line "("UNUSED_c", ctypes.c_uint32), # padding to align to 0x10" (next pointer is valid now): Arena(base=0xb66157a4, top=0x571288, last_remainder=0x543b98, next=0xb5a00018, mem=421888, mempeak=421888) Arena(base=0xb5a00018, top=0xb5a53b40, last_remainder=0xb5a19db0, next=0xb5900018, mem=344064, mempeak=344064) Arena(base=0xb5900018, top=0xb59c19f8, last_remainder=0xb59ae3c8, next=0xb5b00018, mem=868352, mempeak=868352) Arena(base=0xb5b00018, top=0xb5b0f298, last_remainder=0xb5b015c0, next=0xb66157a4, mem=135168, mempeak=135168) ### Minimalist test case _No response_ ### Additional context? _No response_