🔧(helm) add celery deployment

We need to configure a deployment dedicated to celery. It is a copy of
the backend one with modification made where it is specific to celery

src/helm/env.d/dev/values.impress.yaml.gotmpl

@@ -56,6 +56,7 @@ backend:
     POSTGRES_USER: dinum
     POSTGRES_PASSWORD: pass
     REDIS_URL: redis://default:pass@redis-master:6379/1
+    DJANGO_CELERY_BROKER_URL: redis://default:pass@redis-master:6379/1
     AWS_S3_ENDPOINT_URL: http://minio.impress.svc.cluster.local:9000
     AWS_S3_ACCESS_KEY_ID: root
     AWS_S3_SECRET_ACCESS_KEY: password