Fix Cmd/Ctrl + Enter in the composer triggering confirmation dialog action (#36870)

app/javascript/mastodon/features/compose/components/compose_form.jsx

@@ -102,6 +102,7 @@ class ComposeForm extends ImmutablePureComponent {
   handleKeyDownPost = (e) => {
     if (e.key.toLowerCase() === 'enter' && (e.ctrlKey || e.metaKey)) {
         this.handleSubmit();
+        e.preventDefault();
     }
     this.blurOnEscape(e);
   };