tests(mailer): use new contact request template namespace

Author: maxperei

tests/data/config/packages/test/sylius_mailer.yaml

@@ -4,4 +4,4 @@ sylius_mailer:
             enabled: false
         my_dummy_form_type:
             subject: dummy.test
-            template: "@SyliusShop/Email/contactRequest.html.twig"
+            template: "@SyliusCore/Email/contactRequest.html.twig"