Patch python scripts in clang package to use raw strings (or double-escapes) for regular expression patterns

I thought I had already opened an issue about this, but I don't see it in the list.

When working on irods/irods#7823, I ran into the same problem as irods/irods#7741 with the python scripts in the clang package. Let's add another patch to our clang package to fix this so that our github actions can be updated to the latest Ubuntu LTS.
See llvm/llvm-project#94028