Delete duplicate balsamiq viewer tests

spec/javascripts/blob/balsamiq/balsamiq_viewer_browser_spec.js

-// this file can't be migrated to jest because it relies on the browser to perform integration tests:
-//  see: https://gitlab.com/gitlab-org/gitlab/-/issues/194207#note_301878738
-import { FIXTURES_PATH } from 'spec/test_constants';
-import BalsamiqViewer from '~/blob/balsamiq/balsamiq_viewer';
-
-const bmprPath = `${FIXTURES_PATH}/blob/balsamiq/test.bmpr`;
-
-describe('Balsamiq integration spec', () => {
-  let container;
-  let endpoint;
-  let balsamiqViewer;
-
-  preloadFixtures('static/balsamiq_viewer.html');
-
-  beforeEach(() => {
-    loadFixtures('static/balsamiq_viewer.html');
-
-    container = document.getElementById('js-balsamiq-viewer');
-    balsamiqViewer = new BalsamiqViewer(container);
-  });
-
-  describe('successful response', () => {
-    beforeEach(done => {
-      endpoint = bmprPath;
-
-      balsamiqViewer
-        .loadFile(endpoint)
-        .then(done)
-        .catch(done.fail);
-    });
-
-    it('does not show loading icon', () => {
-      expect(document.querySelector('.loading')).toBeNull();
-    });
-
-    it('renders the balsamiq previews', () => {
-      expect(document.querySelectorAll('.previews .preview').length).not.toEqual(0);
-    });
-  });
-
-  describe('error getting file', () => {
-    beforeEach(done => {
-      endpoint = 'invalid/path/to/file.bmpr';
-
-      balsamiqViewer
-        .loadFile(endpoint)
-        .then(done.fail, null)
-        .catch(done);
-    });
-
-    it('does not show loading icon', () => {
-      expect(document.querySelector('.loading')).toBeNull();
-    });
-
-    it('does not render the balsamiq previews', () => {
-      expect(document.querySelectorAll('.previews .preview').length).toEqual(0);
-    });
-  });
-});