gh-98940: Fix Mac/Extras.install.py File filter bug (GH-98943)

Slightly simplify the script and fix a case issue in the name of ``.DS_Store`` files.

(cherry picked from commit ea88d34de27ba2b3acaeb03c7dc7829dff40ea5c)

Co-authored-by: zhangbo <zhangbo2012@outlook.com>
Co-authored-by: Nikita Sobolev <mail@sobolevn.me>