develop doesn't install DOM extension by default

.github/workflows/tests.yml

@@ -25,7 +25,7 @@ jobs:
       uses: shivammathur/setup-php@develop
       with:
         php-version: ${{ matrix.php-versions }}
-        extensions: gd, pdo_sqlite3, sqlite3
+        extensions: dom, gd, pdo_sqlite3, sqlite3
     - name: Remove composer lock
       run: rm composer.lock
     - name: Setup PHPunit