Include GD workflow extension

Author: MGatner

.github/workflows/test.yml

@@ -29,7 +29,7 @@ jobs:
         with:
           php-version: ${{ matrix.php-versions }}
           tools: composer, pecl, phpunit
-          extensions: intl, json, mbstring, mysqlnd, xdebug, xml, sqlite3
+          extensions: intl, json, mbstring, gd, mysqlnd, xdebug, xml, sqlite3
           coverage: xdebug
 
       - name: Get composer cache directory