Git: Ignore patch related files, so they can't be accidentally committed.

This duplicates the changes in [39360] for git.

See #38727.


Built from https://develop.svn.wordpress.org/trunk@39361


git-svn-id: https://core.svn.wordpress.org/trunk@39301 1a063a9b-81f0-0310-95a4-ce76da25c4cd