Workflow for auto releasing on GH

[leuchtum]

Continuing on #283 I suggest to add a workflow for auto releasing on GitHub. This can be done by using the action gh-release. One can configure it, so that it auto generates the release notes as well (Same outcome as using the button from the web GUI).

I marked this as draft for two reasons:

• Need to discuss if combine this into the existing workflow .github/workflows/deploy.yml
• The job in this PR filters the tag, as linopy uses v*.*.* as the tag for releases and you don't want to make a release for every tag. Need to discuss if adding this filter to the .github/workflows/deploy.yml as well.

[leuchtum]

Checks failed due to codecov, same problem as in #290