add qemu step for cross-platform builds and explicitly set platform again

Author: marwan37

.github/workflows/build-push-codespace.yml

@@ -106,9 +106,15 @@ jobs:
         id: timestamp
         run: echo "timestamp=$(date -u +'%Y%m%d%H%M%S')" >> $GITHUB_OUTPUT
 
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
       - name: Set up Docker Buildx
         if: steps.check.outputs.exists == 'true'
         uses: docker/setup-buildx-action@v3
+        with:
+          platforms: linux/amd64
+          install: true
 
       - name: Login to DockerHub
         if: steps.check.outputs.exists == 'true'
@@ -132,6 +138,7 @@ jobs:
         with:
           context: .
           file: ${{ matrix.project }}/Dockerfile.codespace
+          platforms: linux/amd64 # Force amd64 build
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}