Update Swift.gitignore

[zohairhadi]

Reasons for making this change:

.DS_Store don’t add to your project and could leak data from other file names you didn’t stage for checkin.

Links to documentation supporting these rule changes: https://apple.stackexchange.com/questions/471585/is-it-dangerous-to-leave-ds-store-files-left-in-git-commit-history#:~:text=If%20you're%20really%20worried,be%20necessary%20for%20your%20protection.&text=I%20would%20remove%20them%20git,didn't%20stage%20for%20checkin.

[KosFM]

I think this is not a Swift related rule. I think it needs to be added to macOS.gitignore and it already exists in there. https://github.com/github/gitignore/blob/8779ee73af62c669e7ca371aaab8399d87127693/Global/macOS.gitignore#L2

[github-actions[bot]]

This PR is stale because there have been no updates in 90 days. It will close after 180 days of inactivity. Leave a comment if you want to keep it open :smile:

[wirecat]

👋 @zohairhadi We don't currently accept OS specific rules into templates other than the OS template in globals.