chore: add cache docker layers step to docker.yaml (#189)

Signed-off-by: Gaius <gaius.qi@gmail.com>

.github/workflows/docker.yml

@@ -43,6 +43,14 @@ jobs:
       - name: Setup Docker Buildx
         uses: docker/setup-buildx-action@v3
 
+      - name: Cache Docker layers
+        uses: actions/cache@v3
+        with:
+          path: /tmp/.buildx-cache
+          key: ${{ runner.os }}-buildx-${{ github.sha }}
+          restore-keys: |
+            ${{ runner.os }}-buildx-
+
       - name: Login Docker Hub
         uses: docker/login-action@v3
         with:
@@ -72,3 +80,5 @@ jobs:
             dragonflyoss/client:${{ steps.get_version.outputs.VERSION }}
             ghcr.io/${{ env.IMAGE_REPOSITORY }}:${{ steps.get_version.outputs.VERSION }}
           push: true
+          cache-from: type=local,src=/tmp/.buildx-cache
+          cache-to: type=local,dest=/tmp/.buildx-cache-new