Resolve #3289386 "Automated drupal 10"

Closes #3289386

Replicated Drupal rector fixes, and added a composer.json file.

tests/src/Functional/AdminPageTest.php

@@ -33,7 +33,7 @@ class AdminPageTest extends BrowserTestBase {
   public function testAdminPage() {
     $this->drupalLogin($this->rootUser);
     $this->drupalGet('admin');
-    $this->assertResponse(200);
+    $this->assertSession()->statusCodeEquals(200);
 
     // Ensure that the test is not marked as risky because of no assertions.
     // see https://gitlab.com/weitzman/drupal-test-traits/-/commit/82bf5059908f9073b3468cb7313960da72176d9a