Include RTS' dependencies for Docker image (#7773)

(cherry picked from commit 48e2a3d01a)

.github/workflows/github-release.yml

@@ -172,12 +172,18 @@ jobs:
           ls -l dist
 
       # Upload the build artifact so that it can be used by the test & deploy job in the workflow
-      - name: Upload server build bundle
+      - name: Upload RTS build bundle
         uses: actions/upload-artifact@v2
         with:
           name: rts-build
           path: app/rts/dist/
 
+      - name: Upload RTS dependencies bundle
+        uses: actions/upload-artifact@v2
+        with:
+          name: rts-build-deps
+          path: app/rts/node_modules/
+
   package:
     needs: [prelude, buildClient, buildServer, buildRts]
 
@@ -205,6 +211,12 @@ jobs:
           name: rts-build
           path: app/rts/dist
 
+      - name: Download the rts dependencies artifact
+        uses: actions/download-artifact@v2
+        with:
+          name: rts-build-deps
+          path: app/rts/node_modules/
+
       - name: Build and push client image
         working-directory: app/client
         run: |