Add a manual GH action to build artifacts.

.github/workflows/build-artifacts.yml

@@ -0,0 +1,75 @@
+name: Build Artifacts
+
+on:
+  workflow_dispatch:
+    # This input is needed in order to build commits that existed before this
+    # workflow was added.
+    inputs:
+      target_commit:
+        description: 'The commit to build.'
+        required: true
+        type: string
+
+jobs:
+  build-linux-artifact:
+    runs-on: ubuntu-20.04
+
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        ref: ${{ inputs.target_commit }}
+    - name: make
+      run: make
+    # This step does a stupid double-wrapping but is necessary because
+    # upload-artifact uses a zip command (which cannot be disabled) that
+    # removes executable bits.
+    - name: package
+      run: tar cvfz protobufjson-linux.tar.gz JsonToProto  ProtoToJson
+    - uses: actions/upload-artifact@v4
+      with:
+        name: protobufjson-linux-${{ inputs.target_commit }}.tar.gz
+        path: protobufjson-linux.tar.gz
+        if-no-files-found: error
+        compression-level: 0
+
+  build-osx-intel-artifact:
+    runs-on: macos-13
+
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        ref: ${{ inputs.target_commit }}
+    - name: make
+      run: make
+    # This step does a stupid double-wrapping but is necessary because
+    # upload-artifact uses a zip command (which cannot be disabled) that
+    # removes executable bits.
+    - name: package
+      run: tar cvfz protobufjson-macos-intel.tar.gz JsonToProto  ProtoToJson
+    - uses: actions/upload-artifact@v4
+      with:
+        name: protobufjson-macos-intel-${{ inputs.target_commit }}.tar.gz
+        path: protobufjson-macos-intel.tar.gz
+        if-no-files-found: error
+        compression-level: 0
+
+  build-osx-arm-artifact:
+    runs-on: macos-latest
+
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        ref: ${{ inputs.target_commit }}
+    - name: make
+      run: make
+    # This step does a stupid double-wrapping but is necessary because
+    # upload-artifact uses a zip command (which cannot be disabled) that
+    # removes executable bits.
+    - name: package
+      run: tar cvfz protobufjson-macos-arm.tar.gz JsonToProto  ProtoToJson
+    - uses: actions/upload-artifact@v4
+      with:
+        name: protobufjson-macos-arm-${{ inputs.target_commit }}.tar.gz
+        path: protobufjson-macos-arm.tar.gz
+        if-no-files-found: error
+        compression-level: 0