tests: Make PHPUnit data providers static

Initally used a new sniff with autofix (T333745)

Bug: T332865
Change-Id: I845972941b3e0c330a59edef72c3b90902a8b722

tests/phpunit/ServiceWiringTest.php

@@ -25,7 +25,7 @@ class ServiceWiringTest extends MediaWikiIntegrationTestCase {
 		$this->addToAssertionCount( 1 );
 	}
 
-	public function provideService() {
+	public static function provideService() {
 		$wiring = require __DIR__ . '/../../includes/ServiceWiring.php';
 		foreach ( $wiring as $name => $_ ) {
 			yield $name => [ $name ];