Make PHPStan not nag about changing values in $GLOBALS (see contao#2789)

Description
-----------

| Q                | A
| -----------------| ---
| Fixed issues     | -
| Docs PR or issue | -

Fixes the issues reported in the CI.

Commits
-------

d73cf13 make PHPStan not nag about changing values in $GLOBALS
5c03c62 CS

core-bundle/tests/Config/Loader/XliffFileLoaderTest.php

@@ -135,6 +135,7 @@ public function testOverridesKeysInLanguageArray(): void
         $loader = new XliffFileLoader($this->getFixturesDir().'/app', true);
         $loader->load($this->getFixturesDir().'/vendor/contao/test-bundle/Resources/contao/languages/en/default.xlf', 'en');
 
+        $this->assertIsArray($GLOBALS['TL_LANG']['MSC']['third']);
         $this->assertSame('This is the third source', $GLOBALS['TL_LANG']['MSC']['third']['with'][1]);
     }
 }

phpstan.neon.dist

@@ -29,6 +29,11 @@ parameters:
             message: '#PHPDoc tag @param references unknown parameter: \$options#'
             path: %currentWorkingDirectory%/core-bundle/src/Image/PictureFactoryInterface.php
 
+        # Ignore PHPStan not being able to trace changes in $GLOBALS
+        -
+            message: '#Call to method PHPUnit\\Framework\\Assert::assertSame\(\) with .* will always evaluate to false\.#'
+            path: %currentWorkingDirectory%/core-bundle/tests/Framework/ContaoFrameworkTest.php
+
         # Ignore the wrong return type hint of the UrlGeneratorInterface::generate() method
         - '#Method Contao\\CoreBundle\\Picker\\AbstractPickerProvider::generateUrl\(\) never returns null so it can be removed from the return typehint\.#'