Fix caddy-docker issue preventing docker-compose up to work

See [this](api-platform/api-platform#2452)
for more information

Dockerfile

@@ -122,7 +122,7 @@ RUN set -eux; \
 RUN rm -f .env.local.php
 
 # Build Caddy with the Mercure and Vulcain modules
-FROM caddy:2.6-builder-alpine AS app_caddy_builder
+FROM caddy:2.7-builder-alpine AS app_caddy_builder
 
 RUN xcaddy build \
 	--with github.com/dunglas/mercure \
@@ -131,7 +131,7 @@ RUN xcaddy build \
 	--with github.com/dunglas/vulcain/caddy
 
 # Caddy image
-FROM caddy:2.6-alpine AS app_caddy
+FROM caddy:2.7-alpine AS app_caddy
 
 WORKDIR /srv/app