Issue #3164965 by shetpooja04, Hardik_Patel_12: Unused variable $source in...

Issue #3164965 by shetpooja04, Hardik_Patel_12: Unused variable $source in help_topics module, HelpTopicTwigLoaderTest.php

core/modules/help_topics/tests/src/Unit/HelpTopicTwigLoaderTest.php

@@ -67,7 +67,7 @@ public function testGetSourceContextException() {
     $this->expectException(LoaderError::class);
     $this->expectExceptionMessage("Malformed YAML in help topic \"vfs://root/modules/test/help_topics/test.invalid_yaml.html.twig\":");
 
-    $source = $this->helpLoader->getSourceContext('@' . HelpTopicTwigLoader::MAIN_NAMESPACE . '/test.invalid_yaml.html.twig');
+    $this->helpLoader->getSourceContext('@' . HelpTopicTwigLoader::MAIN_NAMESPACE . '/test.invalid_yaml.html.twig');
   }
 
   /**