[clang] [clang-tools-extra] [clang-tidy] [Modules] Skip checking decls in clang-tidy (PR #145630)

[Zeyi Xu via cfe-commits]

zeyi2 wrote:

Hi, I noticed a CI failure introduced by this PR:

https://github.com/llvm/llvm-project/actions/runs/23287741820

Seems that the `cxx20-modules.cppm` test is not functioning as expected.

https://github.com/llvm/llvm-project/pull/145630