Do not optimize/smush/ImageOptim GIFs. Most are either not reduced in size or...

Do not optimize/smush/ImageOptim GIFs. Most are either not reduced in size or reduced only couple of bytes but the optimization messes with the transparency/matte. Fixes #22536, see #22381

git-svn-id: https://core.svn.wordpress.org/trunk@22829 1a063a9b-81f0-0310-95a4-ce76da25c4cd