Changeset 60636 for trunk/src/wp-admin/css/forms.css

Administration: Remove obsolete placeholder styles.

Remove the browser-prefixed placeholder styling -ms-input-placeholder and custom opacity for -moz-placeholder. --ms-input-placeholder is no longer used by any supported browsers and Firefox now uses color-mix to set placeholder colors instead of reduced opacity.

Props afercia, abcd95, sabernhardt, aialvi, joedolson.
Fixes #63030.