Description of the problem, including code/CLI snippet

It seems that the code we use to create a release from a tag here has been deprecated and removed

We should update to use the new release API

I'll try to investigate a little later tonight as it is blocking my team for some automated release tools.

Expected Behavior

• set_release_description() create or update a release

Actual Behavior

• 404 error

Specifications

• python-gitlab version: 2.8 (and 2.5)
• API version you are using (v3/v4): v4
• Gitlab server version (or gitlab.com): gitlab.com