Use vitest globals (#27102) (#27311)

Backport #27102 by @silverwind

Enable [globals](https://vitest.dev/config/#globals) in vitest, reducing
the noise in test files.

Co-authored-by: silverwind <me@silverwind.io>

web_src/js/features/common-issue-list.test.js

@@ -1,4 +1,3 @@
-import {test, expect} from 'vitest';
 import {parseIssueListQuickGotoLink} from './common-issue-list.js';
 
 test('parseIssueListQuickGotoLink', () => {

web_src/js/features/repo-code.test.js

@@ -1,4 +1,3 @@
-import {test, expect} from 'vitest';
 import {singleAnchorRegex, rangeAnchorRegex} from './repo-code.js';
 
 test('singleAnchorRegex', () => {

web_src/js/features/repo-findfile.test.js

@@ -1,4 +1,3 @@
-import {describe, expect, test} from 'vitest';
 import {strSubMatch, calcMatchedWeight, filterRepoFilesWeighted} from './repo-findfile.js';
 
 describe('Repo Find Files', () => {