ML model inference support to be stripped from dclab

[paulmueller]

Since ML model inference via ancillary features is not used AFAIK, and it has become a burden to maintain (failing tests with tensorflow, long pipeline times), I am planning to strip this functionality from dclab. This also affects the corresponding functionality in Shape-Out (loading models).

This will not affect the presence of the ml_score_??? features and I might keep in the registration of features (where feature names can be mapped to proper axes labels).

Please comment here if you have an opinion.

[paulmueller]

TODO:

• Replace Python "3.11" with "3.x" in GHA (tensorflow always lacked behind)