Fix beforeEach usage in labelManager tests

Author: DiogoRibeiro7

tests/labelManager.test.ts

@@ -1,4 +1,4 @@
-import { describe, it, expect, vi } from 'vitest';
+import { describe, it, expect, vi, beforeEach } from 'vitest';
 import * as core from '@actions/core';
 import { labelsFromMetadata, ensureLabelExists } from '../src/core/labelManager';
 
@@ -55,6 +55,4 @@ describe('ensureLabelExists', () => {
     });
   });
 });
-function beforeEach(setupFunction: () => void): void {
-  setupFunction();
-}
+