[Sanitizers][ABI] Remove too strong assert in asan_abi_shim (#81696)

Recently we enabled building the shim for arm64_32 arch. On this arch,
sizeof(uptr) == sizeof(unsigned long) == 4 - so this assert will fail in
runtime.

Need to just remove this assert

rdar://122927166



Co-authored-by: Mariusz Borsa <m_borsa@apple.com>