feat: refactor dockerfiles

* combine dev and prod into multi-stages dockerfile
* replace node with node:20-alpine to reduce image size

.github/workflows/ci_cd.yml

@@ -69,6 +69,7 @@ jobs:
         with:
           context: .
           file: ./server/Dockerfile
+          target: prod
           push: true
           tags: docker.io/${{ secrets.DOCKERHUB_USERNAME }}/linux-odyssey:backend
 
@@ -77,6 +78,7 @@ jobs:
         with:
           context: .
           file: ./app/Dockerfile
+          target: prod
           push: true
           tags: docker.io/${{ secrets.DOCKERHUB_USERNAME }}/linux-odyssey:app
 
@@ -85,6 +87,7 @@ jobs:
         with:
           context: .
           file: ./packages/analytics/Dockerfile
+          target: prod
           push: true
           tags: docker.io/${{ secrets.DOCKERHUB_USERNAME }}/linux-odyssey:analytics