Migrate workflows to Blacksmith (#428)

Co-authored-by: blacksmith-sh[bot] <157653362+blacksmith-sh[bot]@users.noreply.github.com>

.github/workflows/docker.yml

@@ -26,7 +26,7 @@ jobs:
     pr-smoke:
         name: PR Docker Smoke
         if: github.event_name == 'pull_request'
-        runs-on: ubuntu-latest
+        runs-on: blacksmith-2vcpu-ubuntu-2404
         timeout-minutes: 25
         permissions:
             contents: read
@@ -34,8 +34,8 @@ jobs:
             - name: Checkout repository
               uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
 
-            - name: Set up Docker Buildx
-              uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3
+            - name: Setup Blacksmith Builder
+              uses: useblacksmith/setup-docker-builder@v1
 
             - name: Extract metadata (tags, labels)
               id: meta
@@ -46,14 +46,13 @@ jobs:
                       type=ref,event=pr
 
             - name: Build smoke image
-              uses: docker/build-push-action@ca052bb54ab0790a636c9b5f226502c73d547a25 # v5
+              uses: useblacksmith/build-push-action@v2
               with:
                   context: .
                   push: false
                   load: true
                   tags: zeroclaw-pr-smoke:latest
                   labels: ${{ steps.meta.outputs.labels }}
-                  cache-from: type=gha
                   platforms: linux/amd64
 
             - name: Verify image
@@ -71,8 +70,8 @@ jobs:
             - name: Checkout repository
               uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
 
-            - name: Set up Docker Buildx
-              uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3
+            - name: Setup Blacksmith Builder
+              uses: useblacksmith/setup-docker-builder@v1
 
             - name: Log in to Container Registry
               uses: docker/login-action@c94ce9fb468520275223c153574b00df6fe4bcc9 # v3
@@ -103,11 +102,9 @@ jobs:
                   echo "tags=${TAGS}" >> "$GITHUB_OUTPUT"
 
             - name: Build and push Docker image
-              uses: docker/build-push-action@ca052bb54ab0790a636c9b5f226502c73d547a25 # v5
+              uses: useblacksmith/build-push-action@v2
               with:
                   context: .
                   push: true
                   tags: ${{ steps.meta.outputs.tags }}
-                  cache-from: type=gha
-                  cache-to: type=gha,mode=max
                   platforms: ${{ startsWith(github.ref, 'refs/tags/') && 'linux/amd64,linux/arm64' || 'linux/amd64' }}