[TASK] Move a repository test from unit to functional (#1484)

Unit tests for repositories are quite a hassle as we then need to
set up all dependencies in `setUp()` ourselves.

So convert the test to a functional tests where we can rely on the
container to create and initialize the subject for us.

Tests/Functional/Domain/Repository/TeaRepositoryTest.php

@@ -8,6 +8,7 @@
 use TTN\Tea\Domain\Repository\TeaRepository;
 use TYPO3\CMS\Extbase\Domain\Model\FileReference;
 use TYPO3\CMS\Extbase\Persistence\PersistenceManagerInterface;
+use TYPO3\CMS\Extbase\Persistence\Repository;
 use TYPO3\TestingFramework\Core\Functional\FunctionalTestCase;
 
 /**
@@ -31,6 +32,14 @@ protected function setUp(): void
         $this->subject = $this->get(TeaRepository::class);
     }
 
+    /**
+     * @test
+     */
+    public function isRepository(): void
+    {
+        self::assertInstanceOf(Repository::class, $this->subject);
+    }
+
     /**
      * @test
      */