Add macOS specific ignore for .DS_Store files

[breakcito]

Link to the application or project's homepage

https://github.com/github/gitignore

Reasons for making this change

Add *.DS_Store* to Python.gitignore to prevent macOS Finder metadata files from being accidentally committed to Python projects.

.DS_Store files are automatically generated by macOS and do not contain project source code or Python-specific project data. Ignoring them helps keep repositories free of operating-system-specific metadata and avoids unnecessary changes appearing in version control.

Links to documentation supporting these rule changes

• GitHub Gitignore repository: https://github.com/github/gitignore
• GitHub documentation on ignoring files: https://docs.github.com/en/get-started/git-basics/ignoring-files

Merge and Approval Steps

• I have read the contribution guidelines and understand my PR will be closed if it doesn't meet these guidelines.

Once submitted, I will wait for a GitHub maintainer to review the change and address any requested feedback.