Issue #3289993: Automated Drupal 10 compatibility fixes

tests/src/Kernel/ReferenceFinderTest.php

@@ -65,7 +65,7 @@ class ReferenceFinderTest extends KernelTestBase {
   /**
    * {@inheritdoc}
    */
-  public function setUp() {
+  public function setUp(): void {
     parent::setUp();
     $this->installConfig(['filter']);
     $this->installSchema('system', 'sequences');