Mark RUNTIME_GID as an argument

Dockerfile

@@ -194,6 +194,7 @@ FROM --platform=${BUILDARCH} node:lts AS frontend-build
 ARG BUILDARCH
 ARG BUILD_FRONTEND=0
 ARG RUNTIME_UID
+ARG RUNTIME_GID
 
 ARG NODE_ENV=production
 ENV NODE_ENV=$NODE_ENV