Enhance GitHub Actions for multi-arch Docker builds

Updated build workflow to support multi-architecture builds for both amd64 and arm64 platforms, including manifest creation.

Author: freemankevin

.github/workflows/build.yml

@@ -9,28 +9,52 @@ jobs:
     strategy:
       matrix:
         torch-version: ["2.7.0"]
+        include:
+          - arch: amd64
+            platform: linux/amd64
+          - arch: arm64
+            platform: linux/arm64
     steps:
       - name: Checkout code
         uses: actions/checkout@v4
+      
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v3
         with:
-          platforms: arm64
+          platforms: ${{ matrix.arch }}
+      
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
+      
       - name: Login to Docker Hub
         uses: docker/login-action@v3
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
+      
       - name: Build and push
         uses: docker/build-push-action@v6
         with:
           context: .
-          platforms: linux/amd64,linux/arm64
+          platforms: ${{ matrix.platform }}
           push: true
           tags: |
-            freelabspace/python-local:3.10
-            freelabspace/python-local:latest
+            freelabspace/python-local:3.10-${{ matrix.arch }}
           build-args: |
             TORCH_VERSION=${{ matrix.torch-version }}
+  
+  create-manifest:
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Login to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+      
+      - name: Create and push manifest for latest
+        run: |
+          docker buildx imagetools create -t freelabspace/python-local:latest \
+            freelabspace/python-local:3.10-amd64 \
+            freelabspace/python-local:3.10-arm64