CI: attest-build-provenance: fix a subject-path issue (461)

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

Author: AkihiroSuda

.github/workflows/release.yaml

@@ -53,7 +53,9 @@ jobs:
     - uses: actions/attest-build-provenance@v1
       if: github.event_name == 'push' && startsWith(github.ref, 'refs/tags/v')
       with:
-        subject-path: /tmp/artifact/* /tmp/SHA256SUMS
+        subject-path: |
+          /tmp/artifact/*
+          /tmp/SHA256SUMS
     - name: "Create release"
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}