[clang-tools-extra] added option `google-readability-namespace-comments.AllowNoNamespaceComments` (PR #124265)

[Congcong Cai via cfe-commits]

https://github.com/HerrCai0907 commented:

Could you organize test. It looks like copy from other tests and have some noise which has nothing to do with the function of the current PR.

Also, please rebase to main since release note is cleared

https://github.com/llvm/llvm-project/pull/124265