Irrelevant compilation of include/._clangd_helper_file for packaging and problematic name #2345

#2341 was great improvement.

One final nitpick is that include/._clangd_helper_file is always compiled even though it's not needed for packaging.

This is not a problem most of times, however, if for whatever reason you're untar-ing this repo on MacOS (like when using a cached git-clone) the ._ file may be mistaken as AppleDouble metadata file and skipped, causing a hard compilation error due to missing files.