[CRON] Sync with copier template

[github-actions]

This PR updates the project to the latest version of scipp's copier-template.
Remember to check for any conflicts and resolve them.

[MridulS]

The action runs fine! https://github.com/scipp/esssans/actions/workflows/copier.yml

It can be triggered manually via workflow dispatch or there will be a weekly cron job to sync with upstream template.

[SimonHeybrock]

... but CI jobs do not run?

[MridulS]

Yeah seems like need to use a PAT :/
Github prevents non workflow_dispatch triggers by bots
https://docs.github.com/en/actions/security-guides/automatic-token-authentication#using-the-github_token-in-a-workflow

There are some workarounds https://github.com/peter-evans/create-pull-request/blob/main/docs/concepts-guidelines.md#workarounds-to-trigger-further-workflow-runs (let's try the close and open pull request one)

[MridulS]

Well that worked, it's indeed annoying to close and open a PR to trigger the build but it seems like the quickest one assuming we don't want to create a new scipp-bot account on github.