ci(release): run binary + docker builds on Blacksmith

Scoped replacement for #8. Only `tero-release.yaml` is touched — the
upstream-Vector CI workflows stay on standard runners so future syncs
don't conflict on every file.

Heavy compile jobs get the bigger runner; docker assembly stays on 4vcpu.

- build-binary matrix: blacksmith-8vcpu-ubuntu-2404 / -arm
- build-docker matrix: blacksmith-4vcpu-ubuntu-2404 / -arm
- merge-docker-manifest: blacksmith-4vcpu-ubuntu-2404
- docker/setup-buildx-action -> useblacksmith/setup-docker-builder
- docker/build-push-action -> useblacksmith/build-push-action
  (drops manual cache-from/to: type=gha; Blacksmith's colocated layer
  cache is handled by the builder automatically)

Untouched: prepare, upload-release-assets, summary — they don't build
anything, so they stay on ubuntu-24.04. actions/cache@v4 is also left
alone; it auto-interacts with Blacksmith's cache backend when the job
runs on a Blacksmith runner.

Author: jaronoff97

.github/workflows/tero-release.yaml

@@ -76,10 +76,10 @@ jobs:
       matrix:
         include:
           - arch: amd64
-            runner: ubuntu-24.04
+            runner: blacksmith-8vcpu-ubuntu-2404
             triple: x86_64-unknown-linux-gnu
           - arch: arm64
-            runner: arm-4-core
+            runner: blacksmith-8vcpu-ubuntu-2404-arm
             triple: aarch64-unknown-linux-gnu
     steps:
       - name: Checkout
@@ -189,10 +189,10 @@ jobs:
       matrix:
         include:
           - arch: amd64
-            runner: ubuntu-24.04
+            runner: blacksmith-4vcpu-ubuntu-2404
             platform: linux/amd64
           - arch: arm64
-            runner: ubuntu-24.04-arm
+            runner: blacksmith-4vcpu-ubuntu-2404-arm
             platform: linux/arm64
     steps:
       - name: Checkout
@@ -209,8 +209,11 @@ jobs:
           chmod +x "${{ matrix.arch }}/vector"
           ls -la "${{ matrix.arch }}/"
 
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+      - name: Set up Blacksmith Docker builder
+        # Blacksmith's setup-docker-builder wraps buildx and points the build
+        # cache at Blacksmith's colocated layer cache, so we drop the manual
+        # `cache-from`/`cache-to: type=gha` below — it's handled automatically.
+        uses: useblacksmith/setup-docker-builder@v1
 
       - name: Log in to Container Registry
         if: ${{ !inputs.dry_run }}
@@ -222,14 +225,12 @@ jobs:
 
       - name: Build and push by digest
         id: build
-        uses: docker/build-push-action@v6
+        uses: useblacksmith/build-push-action@v2
         with:
           context: .
           file: distribution/docker/tero/Dockerfile
           platforms: ${{ matrix.platform }}
           outputs: type=image,name=${{ env.REGISTRY }}/${{ env.IMAGE_NAME }},push-by-digest=true,name-canonical=true,push=${{ !inputs.dry_run }}
-          cache-from: type=gha,scope=${{ matrix.arch }}
-          cache-to: type=gha,mode=max,scope=${{ matrix.arch }}
 
       - name: Export digest
         if: ${{ !inputs.dry_run }}
@@ -250,7 +251,7 @@ jobs:
 
   merge-docker-manifest:
     name: Merge Docker manifests
-    runs-on: ubuntu-24.04
+    runs-on: blacksmith-4vcpu-ubuntu-2404
     needs: [prepare, build-docker]
     if: ${{ !inputs.dry_run }}
     steps:
@@ -261,8 +262,8 @@ jobs:
           pattern: digests-*
           merge-multiple: true
 
-      - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v3
+      - name: Set up Blacksmith Docker builder
+        uses: useblacksmith/setup-docker-builder@v1
 
       - name: Log in to Container Registry
         uses: docker/login-action@v3