add attest

Author: williamstein

.github/workflows/test.yml

@@ -43,3 +43,7 @@ jobs:
       - run: pnpm install
       - run: pnpm build
       - run: pnpm test
+      - name: Attest
+        uses: actions/attest-build-provenance@v2
+        with:
+          subject-path: '${{ github.workspace }}/http-proxy-3'