Remove unused variable in `wp_dashboard_plugins_output()`. Unused since [26144].

props michalzuber.
see #28872.
Built from https://develop.svn.wordpress.org/trunk@29130


git-svn-id: http://core.svn.wordpress.org/trunk@28915 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Media Grid: Remove CSS transition from inline uploader.

props ericlewis.
fixes #28840.
see #28851.
Built from https://develop.svn.wordpress.org/trunk@29131


git-svn-id: http://core.svn.wordpress.org/trunk@28916 1a063a9b-81f0-0310-95a4-ce76da25c4cd
Customizer: Make screen reader text translatable.

see #27406.
Built from https://develop.svn.wordpress.org/trunk@29132


git-svn-id: http://core.svn.wordpress.org/trunk@28917 1a063a9b-81f0-0310-95a4-ce76da25c4cd