fix: use stage as default NODE_ENV

Dockerfile

@@ -14,7 +14,7 @@ WORKDIR /app
 COPY --from=deps /app/node_modules ./node_modules
 COPY . .
 
-ARG NODE_ENV production
+ARG NODE_ENV stage
 # Next.js collects completely anonymous telemetry data about general usage.
 # Learn more here: https://nextjs.org/telemetry
 # Uncomment the following line in case you want to disable telemetry during the build.
@@ -29,7 +29,7 @@ RUN npm run build
 FROM node:18.12.0-alpine AS runner
 WORKDIR /app
 
-ARG NODE_ENV production
+ARG NODE_ENV stage
 # Uncomment the following line in case you want to disable telemetry during runtime.
 # ENV NEXT_TELEMETRY_DISABLED 1