[clang-tools-extra] Make clang print include paths without `../` jumps

[vbvictor]

See #167020 (comment).
We essentially need to remove this line:

llvm-project/clang-tools-extra/clang-tidy/.clang-tidy

Line 3 in 5e4505d

ExcludeHeaderFilterRegex: 'include-cleaner|clang-query'

[llvmbot]

@llvm/issue-subscribers-clang-tidy

Author: Baranov Victor (vbvictor)

See https://github.com//pull/167020#discussion_r2505506435. We essentially need to remove this line: https://github.com/llvm/llvm-project/blob/main/clang-tools-extra/clang-tidy/.clang-tidy#L3

[vbvictor]

Related fix for include-cleaner: #167110