fix: update docker build step to load cache and specify platforms

Author: kunish

.github/workflows/release.yml

@@ -105,10 +105,11 @@ jobs:
           context: .
           builder: ${{ steps.buildx.outputs.name }}
           file: Dockerfile
-          platforms: linux/amd64,linux/arm64
+          load: true
           push: true
+          platforms: linux/amd64,linux/arm64
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
           tags: |
             ghcr.io/metacubex/metacubexd:latest
             ghcr.io/metacubex/metacubexd:${{ needs.release-please.outputs.tag_name }}
-          cache-from: type=gha
-          cache-to: type=gha,mode=max