Build/Test Tools: Remove unused test groups from the 5.0 branch.

Follow up to [50307].

See #50401.

git-svn-id: https://develop.svn.wordpress.org/branches/5.0@50334 602fd350-edb4-49c9-b593-d223f7449a82

Author: desrosj

.github/workflows/phpunit-tests.yml

@@ -278,10 +278,6 @@ jobs:
       - name: Run REST API tests
         run: npm run test:${{ env.PHPUNIT_SCRIPT }} -- --verbose -c phpunit.xml.dist --group restapi-jsclient
 
-      # __fakegroup__ is excluded to force PHPUnit to ignore the <exclude> settings in phpunit.xml.dist.
-      - name: Run (xDebug) tests
-        run: LOCAL_PHP_XDEBUG=true npm run test:php -- -v --group xdebug --exclude-group __fakegroup__
-
       - name: Checkout the WordPress Test Reporter
         if: ${{ github.repository == 'WordPress/wordpress-develop' && github.ref == 'refs/heads/master' && matrix.report }}
         uses: actions/checkout@v2