Update package.yaml

Author: mackysoft

.github/workflows/package.yaml

@@ -34,7 +34,7 @@ jobs:
           UNITY_EMAIL: ${{ secrets.UNITY_EMAIL }}
           UNITY_PASSWORD: ${{ secrets.UNITY_PASSWORD }}
         with:
-          unityVersion: 2020.3.8f1
+          unityVersion: 2021.3.29f1
           buildMethod: MackySoft.PackageTools.Editor.UnityPackageExporter.Export
 
       # Upload