fix(redis): Actually use custom config (#3459)

Follow up to #3427 (comment) where we created and mounted a custom Redis config only to not use it 🤦

docker-compose.yml

@@ -117,6 +117,7 @@ services:
       nofile:
         soft: 10032
         hard: 10032
+    command: ["redis-server", "/usr/local/etc/redis/redis.conf"]
   postgres:
     <<: *restart_policy
     # Using the same postgres version as Sentry dev for consistency purposes