Fix action-gh-release broken in nightly workflow

See softprops/action-gh-release#139.

.github/workflows/nightly.yml

@@ -59,7 +59,7 @@ jobs:
         run: "git tag -f nightly && git push -f origin nightly"
 
       - name: "Create GitHub Release"
-        uses: "softprops/action-gh-release@v1"
+        uses: "softprops/action-gh-release@v0.1.8"
         env:
           GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
         with: