fix: type mismatches and handle nullable values

tests/Config/EmailTextCatalogTest.php

@@ -93,6 +93,9 @@ class EmailTextCatalogTest extends KernelTestCase
     {
         self::bootKernel();
 
-        return self::getContainer()->get(EmailTextCatalog::class);
+        /** @var EmailTextCatalog $catalog */
+        $catalog = self::getContainer()->get(EmailTextCatalog::class);
+
+        return $catalog;
     }
 }