Fix contrast issue in Files app menu

Signed-off-by: Jan C. Borchardt <hey@jancborchardt.net>

core/css/styles.scss

@@ -467,7 +467,9 @@ tr .action:not(.permanent), .selectedActions a {
 }
 
 tr {
-	&:hover .action, &:focus .action, .action.permanent {
+	&:hover .action:not(.menuitem),
+	&:focus .action:not(.menuitem),
+	.action.permanent:not(.menuitem) {
 		opacity: .5;
 	}
 }