Add scrolling to Compare history modal (#23396)

* Compare history modal: allow vertical scrolling

* Update app/javascript/styles/mastodon/components.scss

Co-authored-by: Claire <claire.github-309c@sitedethib.com>

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Co-authored-by: Claire <claire.github-309c@sitedethib.com>

app/javascript/styles/mastodon/components.scss

@@ -5798,6 +5798,7 @@ a.status-card.compact:hover {
   &__container {
     padding: 30px;
     pointer-events: all;
+    overflow-y: auto;
   }
 
   .status__content {