[clang] fix(clang/**.py): fix invalid escape sequences (PR #94029)

[Donát Nagy via cfe-commits]

https://github.com/NagyDonat commented:

The change in `clang/test/Analysis/check-analyzer-fixit.py` is a good step forward, it indeed fixes an invalid escape sequence[1].

However, I don't see any reason for the changes in `clang/docs/tools/dump_ast_matchers.py`: those were raw strings, so there cannot be "invalid escapes sequences" within them. Please elaborate the reason why you want to apply these changes.

[1]: For readers unfamiliar with Python: the character combination `\-` does not have special meaning in Python string literals; so in older Python version these two characters were directly included into the string. However, this behavior is deprecated and in the future unrecognized escape sequences will cause `SyntaxError` (in non-raw strings).

https://github.com/llvm/llvm-project/pull/94029