fix: prevent installing another Mercure hub (#181)

docker-compose.override.yml

@@ -17,3 +17,6 @@ services:
     volumes:
       - ./docker/caddy/Caddyfile:/etc/caddy/Caddyfile:ro
       - ./public:/srv/app/public:ro
+
+###> symfony/mercure-bundle ###
+###< symfony/mercure-bundle ###

docker-compose.yml

@@ -54,7 +54,13 @@ services:
         published: 443
         protocol: udp
 
+# Mercure is installed as a Caddy module, prevent the Flex recipe from installing another service
+###> symfony/mercure-bundle ###
+###< symfony/mercure-bundle ###
+
 volumes:
   php_socket:
   caddy_data:
   caddy_config:
+###> symfony/mercure-bundle ###
+###< symfony/mercure-bundle ###