Stick to numpy<1.24 to fix errors about numba when installing training extras

numpy>=1.24 and mlflow are incompatible for now. Hence the downgrade to be able to install the training extras correctly.

This may be reverted later when mlflow releases a version that doesn't need shap (which needs numba).

assigned to @schneider-y

enabled an automatic merge when the pipeline for 8646c11e succeeds

merged