Fix GitHub Actions Docker build cache configuration

- Re-add Docker Buildx setup (required for cache)
- Use 'type=inline' for cache-to (embeds cache in image)
- Cache from the latest image instead of separate buildcache tag

This fixes the 'Cache export is not supported' error.

Co-Authored-By: Claude <noreply@anthropic.com>

.github/workflows/deploy.yml

@@ -43,6 +43,9 @@ jobs:
             type=sha,prefix={{branch}}-
             type=raw,value=latest,enable={{is_default_branch}}
 
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
       - name: Build and push Docker image
         uses: docker/build-push-action@v5
         with:
@@ -50,8 +53,8 @@ jobs:
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
-          cache-from: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:buildcache
-          cache-to: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:buildcache,mode=max
+          cache-from: type=registry,ref=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest
+          cache-to: type=inline
 
   deploy:
     needs: build-and-push