Build linux-arm64 on an arm runner

Author: ecrousseau

.github/workflows/build.yml

@@ -20,55 +20,49 @@ jobs:
             echo "Tag format is invalid. Expected semantic versioning (e.g., 1.2.3)."
             exit 1
           fi
-  macos:
-    runs-on: macos-latest
+  build:
+    runs-on: ${{ matrix.runs-on }}
     needs:
       - validate
     strategy:
       matrix:
-        arch:
-          - arm64
+        runs-on:
+          - macos-15
+          - ubuntu-24.04
+          - ubuntu-24.04-arm
     steps:
       - uses: actions/checkout@v4
         with:
           repository: apple/swift-protobuf
           ref: ${{ github.ref_name }}
-      - run: |
-          swift build -c release
-          mv .build/release/protoc-gen-swift protoc-gen-swift-macos-${{ matrix.arch }}
-      - uses: actions/upload-artifact@v4
-        with:
-          name: protoc-gen-swift-macos-${{ matrix.arch }}
-          path: protoc-gen-swift-macos-${{ matrix.arch }}
-  linux:
-    runs-on: ubuntu-latest
-    needs:
-      - validate
-    strategy:
-      matrix:
-        arch:
-          - amd64
-          - arm64
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          repository: apple/swift-protobuf
-          ref: ${{ github.ref_name }}
-      - run: |
-          swift build -c release --static-swift-stdlib
-          mv .build/release/protoc-gen-swift protoc-gen-swift-linux-${{ matrix.arch }}
+      - id: build
+        run: |
+          if [[ ${{ matrix.runs-on }} == "macos-15" ]]; then
+            executable="protoc-gen-swift-macos-arm64"
+          elif [[ ${{ matrix.runs-on }} == "ubuntu-24.04" ]]; then
+            executable="protoc-gen-swift-linux-amd64"
+            flags="--static-swift-stdlib"
+          elif [[ ${{ matrix.runs-on }} == "ubuntu-24.04-arm" ]]; then
+            executable="protoc-gen-swift-linux-arm64"
+            flags="--static-swift-stdlib"
+          else
+            echo "unsupported runner type: ${{ matrix.runs-on }}"
+            exit 1
+          fi
+          swift build -c release $flags
+          echo "executable=$executable" | tee -a $GITHUB_OUTPUT
+          mv .build/release/protoc-gen-swift $executable
       - uses: actions/upload-artifact@v4
         with:
-          name: protoc-gen-swift-linux-${{ matrix.arch }}
-          path: protoc-gen-swift-linux-${{ matrix.arch }}
+          name: ${{ steps.build.outputs.executable }}
+          path: ${{ steps.build.outputs.executable }}
   release:
     runs-on: ubuntu-latest
     needs:
-      - macos
-      - linux
+      - build
     steps:
       - uses: actions/download-artifact@v4
-      - run: ls -l; ls -l protoc-gen-swift-*
+      - run: ls -l
       - uses: softprops/action-gh-release@c95fe1489396fe8a9eb87c0abf8aa5b2ef267fda
         with:
           files: '**/protoc-gen-swift-*'