Remove vestigial references to deprecated jQuery dropdown

app/assets/javascripts/pages/projects/compare/index.js

-import initCompareAutocomplete from '~/compare_autocomplete';
-
-document.addEventListener('DOMContentLoaded', () => initCompareAutocomplete());

app/assets/javascripts/pages/projects/merge_requests/creations/new/compare.js

 import $ from 'jquery';
-import initCompareAutocomplete from '~/compare_autocomplete';
 import axios from '~/lib/utils/axios_utils';
 import { localTimeAgo } from '~/lib/utils/datetime_utility';
+import initCompareAutocomplete from './compare_autocomplete';
 import initTargetProjectDropdown from './target_project_dropdown';
 
 const updateCommitList = (url, $loadingIndicator, $commitList, params) => {

app/assets/javascripts/compare_autocomplete.js → app/assets/javascripts/pages/projects/merge_requests/creations/new/compare_autocomplete.js

@@ -2,11 +2,11 @@
 
 import $ from 'jquery';
 import initDeprecatedJQueryDropdown from '~/deprecated_jquery_dropdown';
+import { deprecatedCreateFlash as flash } from '~/flash';
+import axios from '~/lib/utils/axios_utils';
+import { capitalizeFirstCharacter } from '~/lib/utils/text_utility';
+import { __ } from '~/locale';
 import { fixTitle } from '~/tooltips';
-import { deprecatedCreateFlash as flash } from './flash';
-import axios from './lib/utils/axios_utils';
-import { capitalizeFirstCharacter } from './lib/utils/text_utility';
-import { __ } from './locale';
 
 export default function initCompareAutocomplete(limitTo = null, clickHandler = () => {}) {
   $('.js-compare-dropdown').each(function () {

app/assets/javascripts/projects/compare/components/revision_dropdown.vue

@@ -129,7 +129,7 @@ export default {
     <input type="hidden" :name="paramsName" :value="selectedRevision" />
     <gl-dropdown
       class="gl-w-full gl-font-monospace"
-      toggle-class="form-control compare-dropdown-toggle js-compare-dropdown gl-min-w-0"
+      toggle-class="form-control compare-dropdown-toggle gl-min-w-0"
       :text="selectedRevision"
       :header-text="s__('CompareRevisions|Select Git revision')"
       :loading="loading"

app/assets/javascripts/projects/compare/components/revision_dropdown_legacy.vue

@@ -112,7 +112,7 @@ export default {
       <input type="hidden" :name="paramsName" :value="selectedRevision" />
       <gl-dropdown
         class="gl-flex-grow-1 gl-flex-basis-0 gl-min-w-0 gl-font-monospace"
-        toggle-class="form-control compare-dropdown-toggle js-compare-dropdown gl-min-w-0 gl-rounded-top-left-none! gl-rounded-bottom-left-none!"
+        toggle-class="form-control compare-dropdown-toggle gl-min-w-0 gl-rounded-top-left-none! gl-rounded-bottom-left-none!"
         :text="selectedRevision"
         header-text="Select Git revision"
         :loading="loading"