use ubuntu

Author: jinliu9508

.github/workflows/create-release-pr.yml

@@ -46,7 +46,7 @@ jobs:
   # Unity specific steps
   update-version:
     needs: prep
-    runs-on: macos-latest
+    runs-on: ubuntu-latest
     outputs:
       unity_from: ${{ steps.current_versions.outputs.unity_from }}
       ios_from: ${{ steps.current_versions.outputs.ios_from }}