A New, Automated Way To Upgrade fastpages

I submit the Automated Upgrade issue but receive the following error: The set-env command is disabled. Please upgrade to using Environment Files or opt into unsecure command execution by setting the ACTIONS_ALLOW_UNSECURE_COMMANDS environment variable to true. For more information see: https://github.blog/changelog/2020-10-01-github-actions-deprecating-set-env-and-add-path-commands/.

My repo is in here.