fixing unused link

Author: weaverryan

mercure.rst

@@ -719,4 +719,3 @@ it will be handled automatically::
 .. _`the dedicated API Platform documentation`: https://api-platform.com/docs/core/mercure/
 .. _`the online debugger`: https://uri-template-tester.mercure.rocks
 .. _`a feature to test applications using Mercure`: https://github.com/symfony/panther#creating-isolated-browsers-to-test-apps-using-mercure-or-websocket
-.. _`Symfony UX Turbo`: https://symfony.com/bundles/ux-turbo/current/index.html