Change qa-* class references to js-* for squash-checkbox

app/assets/javascripts/vue_merge_request_widget/components/states/squash_before_merge.vue

@@ -36,7 +36,7 @@ export default {
         :disabled="isDisabled"
         type="checkbox"
         name="squash"
-        class="qa-squash-checkbox"
+        class="qa-squash-checkbox js-squash-checkbox"
         @change="$emit('input', $event.target.checked)"
       />
       {{ __('Squash commits') }}

spec/javascripts/vue_mr_widget/components/states/mr_widget_squash_before_merge_spec.js

@@ -21,7 +21,7 @@ describe('Squash before merge component', () => {
   });
 
   describe('checkbox', () => {
-    const findCheckbox = () => wrapper.find('.qa-squash-checkbox');
+    const findCheckbox = () => wrapper.find('.js-squash-checkbox');
 
     it('is unchecked if passed value prop is false', () => {
       createComponent({