build: Updating mediawiki/mediawiki-codesniffer to 20.0.0

Change-Id: I02db015a34f67a8b268feead090d2f6be5658935

includes/ResourceLoaderULSJsonMessageModule.php

@@ -14,7 +14,7 @@ class ResourceLoaderULSJsonMessageModule extends ResourceLoaderModule {
 	/**
 	 * Part of the ResourceLoader module interface.
 	 * Declares the core ext.uls.i18n module as a dependency.
-	 * @param ResourceLoaderContext $context
+	 * @param ResourceLoaderContext|null $context
 	 * @return string[] Module names.
 	 */
 	public function getDependencies( ResourceLoaderContext $context = null ) {