[clang-tools-extra] [clang-doc] switched from using relative to absolute paths (PR #93281)

[Paul Kirth via cfe-commits]

https://github.com/ilovepi commented:

This is almost there. I've left a few minor comments, but I'd like to see better testing here. I'm awfully surprised we don't need to update any test lines, other than the 1 JS check. It would really help to see how the output is changing, if that was captured in the tests.

https://github.com/llvm/llvm-project/pull/93281