Bump [compat] entry: CategoricalArrays="1.0"

[ablaom]

Recall that CategoricalArrays 1.0 introduces new behaviour for levels. The return value is a CategoricalArray instead of raw levels.

As I am not familiar with the codebase for the newer encoders, I have simply replaced all calls levels with rawlevels, where rawlevels mimics the old behaviour: rawlevels(A) = unwrap.(levels(A)).

This PR is needed before important rollout of the CategoricalArrays="1.0" update can happen elsewhere in the MLJ ecosystem. In particular, MLJModels, needs this PR merged before it can do the update.

[EssamWisam]

@ablaom in the ci tests we see ERROR: LoadError: Unsatisfiable requirements detected for package CategoricalArrays [324d7699] it's unexpected for me since you also uped categorical arrays package in project.toml, right?

[ablaom]

Sorry, my bad. This PR needs:

• MLJBase CategoricalArrrays 1.0 update

@EssamWisam Let me ping you when this ready.

[ablaom]

Looks like document generation needs:

• Bump CategoricalArrays to 1.0 in MLJFlux.jl

[ablaom]

Okay, MLJ is also a doc dependency, and we cannot update the MLJ compat entry for CategoricalArrays before MLJTransforms. Documentation has a circular dependency.

Note to self. Centralised, top-level documentation has its advantages. Otherwise, documentation needs to avoid depending on packages on which the package itself is a dependency.

No matter. Failed doc generation does not get deployed. So plan merging, and tagging the doc problem as follow-up issue.

[ablaom]

@EssamWisam Ready for a review

[EssamWisam]

I found that MLJ and others were actually redundant since each tutorial has its own toml file and removed them and now docs deploy.

Looks good to me and will merge.