Remove error flash message from code navigation

This has been removed as the data might not yet be available in
which case we shouldn't really be throwing an
error message.

app/assets/javascripts/code_navigation/store/actions.js

 import api from '~/api';
-import { __ } from '~/locale';
-import createFlash from '~/flash';
 import * as types from './mutation_types';
 import { getCurrentHoverElement, setCurrentHoverElement, addInteractionClass } from '../utils';
 
@@ -10,7 +8,6 @@ export default {
   },
   requestDataError({ commit }) {
     commit(types.REQUEST_DATA_ERROR);
-    createFlash(__('An error occurred loading code navigation'));
   },
   fetchData({ commit, dispatch, state }) {
     commit(types.REQUEST_DATA);

locale/gitlab.pot

@@ -1676,9 +1676,6 @@ msgstr ""
 msgid "An error occurred fetching the dropdown data."
 msgstr ""
 
-msgid "An error occurred loading code navigation"
-msgstr ""
-
 msgid "An error occurred previewing the blob"
 msgstr ""
 

spec/frontend/code_navigation/store/actions_spec.js

 import MockAdapter from 'axios-mock-adapter';
 import testAction from 'helpers/vuex_action_helper';
 import actions from '~/code_navigation/store/actions';
-import createFlash from '~/flash';
 import axios from '~/lib/utils/axios_utils';
 import { setCurrentHoverElement, addInteractionClass } from '~/code_navigation/utils';
 
-jest.mock('~/flash');
 jest.mock('~/code_navigation/utils');
 
 describe('Code navigation actions', () => {
@@ -25,13 +23,6 @@ describe('Code navigation actions', () => {
   describe('requestDataError', () => {
     it('commits REQUEST_DATA_ERROR', () =>
       testAction(actions.requestDataError, null, {}, [{ type: 'REQUEST_DATA_ERROR' }], []));
-
-    it('creates a flash message', () =>
-      testAction(actions.requestDataError, null, {}, [{ type: 'REQUEST_DATA_ERROR' }], []).then(
-        () => {
-          expect(createFlash).toHaveBeenCalled();
-        },
-      ));
   });
 
   describe('fetchData', () => {