Removed failing CobiGen tutorial

[GuentherJulian]

Right now there is a bug in the CobiGen tutorial that is causing the Github pipelines to fail.
The tutorial will be removed for now while the issue is investigated.
There is an issue with the backup of the tutorial here: #200

[github-actions]

Please mark your pull request as draft until it is finished: https://docs.github.com/en/github/collaborating-with-issues-and-pull-requests/changing-the-stage-of-a-pull-request#converting-a-pull-request-to-a-draft

[github-actions]

Thanks for submitting your work on a (new) tutorial!

Some suggestions, which might help:

• Title: Focus on what you want to train in a few words. Don't be too generic
• Tutorial:
  • Address the user directly.
  • Explain why the steps are necessary.
  • Explain what are the results and why are they necessary for your next step.
  • Forward the user to more elaborate documentation on the website (deep links) for further reading

Also please find further help for creating tutorials here or more help regarding the tutorial syntax here.

You can view the generated tutorials of this PR here in a few minutes. You just have to wait for the run of the deployment action to finish.

When you think you are done writing the tutorial try the tutorial on the deveplopment area and check if you explained every step in a way someone who is trying to learn what you are teaching can understand. Ideally ask someone to have a look on what you have done and have that part double checked because this is very important.