provision-with-micromamba github action fails after editing environment.yaml

[Victorlouisdg]

This is not really a big issue with the template itself but can be fixed easily. I created a repo from this template and with the default environment.yaml the conda env creation CI worked. However with some small edits it suddenly failed.

I noticed that provision-with-micromamba has been deprecated:

Run mamba-org/provision-with-micromamba@main
Warning: This action is deprecated and no longer maintained. Please use mamba-org/setup-micromamba instead. See `[https://github.com/mamba-org/provision-with-micromamba#migration-to-setup-micromamba`](https://github.com/mamba-org/provision-with-micromamba#migration-to-setup-micromamba%60) for a migration guide.

So I migrated to setup-micromamba, after which my environment created succeeded again (see commit).