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

[Thorsten Klein via cfe-commits]

thorsten-klein wrote:

@EugeneZelenko What do you think about some additional option `EnforceNoNamespaceComments` in order to enforce that no namespace comment is present?
If you like the idea, I could create some additional PR for introducing this option.

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