CI regression tests don't work with alternative branch for pipeline config

[mleimeister]

Rasa Open Source version

3.0.x

Rasa SDK version

No response

Rasa X version

No response

Python version

3.8

What operating system are you using?

OSX

What happened?

When trying to use a newly added config in the regression tests, following the steps described here, only the dataset is pulled from the branch specified in dataset_branch, but the config is looked up on main.

This is likely due to the hard-coded branch here and should be adapted to also use dataset_branch.

Command / Request

No response

Relevant log output

No response

Definition of Done

• [x] Fix this on main
• [x] Test with some example (e.g. Vincent's logistic regression component)
• [x] Get review from infrastructure squad

[JEM-Mosig]

Thomasz has seen this issue before (-> reviewer ?)