[clang] [llvm] [GitHub][CI] Add running of 'dump_ast_matchers.py' to premerge workflow (PR #165472)

[Baranov Victor via cfe-commits]

vbvictor wrote:

Adding `AST Matchers`/`clang-tidy` maintainers to gather opinion from `dump_ast_matchers.py` standpoint.

https://github.com/llvm/llvm-project/pull/165472