Administration: Remove erroneous transition-delay values from CSS files.

Although unitless zero is allowed for `<length>` CSS data type, it's invalid for `<time>` data type.

Props chetan200891, manuel_84, GaryJ.
Fixes #43195.
Built from https://develop.svn.wordpress.org/trunk@42689


git-svn-id: http://core.svn.wordpress.org/trunk@42517 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/css/dashicons.css

@@ -25,7 +25,7 @@
 	font-style: normal;
 	vertical-align: top;
 	text-align: center;
-	transition: color .1s ease-in 0;
+	transition: color .1s ease-in;
 	-webkit-font-smoothing: antialiased;
 	-moz-osx-font-smoothing: grayscale;
 }