fix: do not handle requests to Mercure as PHP routes (#696)

Co-authored-by: Kévin Dunglas <kevin@dunglas.fr>

.github/workflows/ci.yml

@@ -45,6 +45,9 @@ jobs:
         name: Check HTTPS reachability
         if: false # Remove this line when the homepage will be configured, or change the path to check
         run: curl -vk --fail-with-body https://localhost
+      -
+        name: Check Mercure reachability
+        run: curl -vkI --fail-with-body https://localhost/.well-known/mercure?topic=test
       -
         name: Create test database
         if: false # Remove this line if Doctrine ORM is installed