Fix CW field still having animation in when reduce motion is enabled (#7872)

app/javascript/styles/mastodon/components.scss

@@ -302,12 +302,10 @@
     height: 0;
     transform-origin: bottom;
     opacity: 0.0;
-    transition: all 0.4s ease;
 
     &.spoiler-input--visible {
       height: 47px;
       opacity: 1.0;
-      transition: all 0.4s ease;
     }
   }
 
@@ -568,6 +566,10 @@
   }
 }
 
+.no-reduce-motion .spoiler-input {
+  transition: height 0.4s ease, opacity 0.4s ease;
+}
+
 .emojione {
   font-size: inherit;
   vertical-align: middle;