test the building of an image

.github/workflows/test-frontend.yml

@@ -5,7 +5,7 @@ on:
   push:
 
 jobs:
-  test-frontend:
+  test-frontend-2:
     name: Test Frontend 2
     runs-on: ubuntu-latest
 
@@ -26,3 +26,21 @@ jobs:
       - name: yarn lint:ci
         run: yarn lint:ci
         working-directory: 'packages/frontend-2'
+
+  build-frontend-2:
+    name: Build Frontend 2
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+      - name: Build and export to Docker
+        uses: docker/build-push-action@v6
+        with:
+          # context should remain as the git context
+          file: packages/frontend-2/Dockerfile
+          load: true
+          push: false
+          outputs: type=docker,dest=/tmp/speckle-frontend-2.tar