Resolve #3435988 "Fix phpstan issues"

Closes #3435988

tests/src/FunctionalJavascript/InlineTest.php

@@ -17,7 +17,7 @@ class InlineTest extends TwigjsTestBase {
   /**
    * {@inheritdoc}
    */
-  public static $modules = ['twigjs_test'];
+  protected static $modules = ['twigjs_test'];
 
   /**
    * Test the output is the same.