Generate sigstore signatures in GitHub Actions

Author: dechamps

.github/workflows/continuous-integration.yml

@@ -57,3 +57,20 @@ jobs:
         with:
           name: ASIO401-installer
           path: src/out/installer/*
+  sigstore:
+    runs-on: ubuntu-latest
+    needs: installer
+    permissions:
+      id-token: write
+    steps:
+      - uses: actions/download-artifact@v3
+        with:
+          name: ASIO401-installer
+      - uses: sigstore/[email protected]
+        with:
+          inputs: "*"
+      - uses: actions/upload-artifact@v3
+        with:
+          name: sigstore
+          path: "*.sigstore"
+          if-no-files-found: error