Fix spinner-grow animation (#30504)

* Fix spinner-grow animation

Safari seems to be interpreting the old keyframes animation as incomplete. Adding `transform` to the second frame seems to resolve the issue.

Co-Authored-By: Martijn Cuppens <martijn.cuppens@gmail.com>

scss/_spinners.scss

@@ -34,6 +34,7 @@
   }
   50% {
     opacity: 1;
+    transform: none;
   }
 }