fix(compose): drop runtime: nvidia — use deploy.resources.devices only

Docker on the deploy host doesn't register 'nvidia' as a named runtime
(modern nvidia-container-toolkit hooks via --gpus all / resources.devices
instead). Immich-ml on the same host uses only deploy.resources.devices
with driver: nvidia, which is enough. Drop the legacy runtime line.

Caught on third deploy attempt.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

docker-compose.yml

@@ -18,7 +18,6 @@ services:
     ports:
       - "8994:8994"
     env_file: .env
-    runtime: nvidia
     deploy:
       resources:
         reservations: