Remove lists as acceptable hyperparameter ranges in AutoMLSearch

[angela97lin]

Closes #2015

To support lists as parameters for our components, we are removing lists as acceptable hyperparameter ranges in the pipeline_parameters parameter to AutoMLSearch. This is okay, because users can still use skopt.space.Categorical to achieve the same functionality.

[codecov]

Codecov Report

Merging #2028 (d3594db) into main (cfcfe68) will not change coverage.
The diff coverage is 100.0%.

@@           Coverage Diff           @@
##             main    #2028   +/-   ##
=======================================
  Coverage   100.0%   100.0%           
=======================================
  Files         278      278           
  Lines       22761    22759    -2     
=======================================
- Hits        22752    22750    -2     
  Misses          9        9           

Impacted Files	Coverage Δ
...lml/automl/automl_algorithm/iterative_algorithm.py	100.0% <ø> (ø)
evalml/tests/automl_tests/test_automl.py	100.0% <100.0%> (ø)
...lml/tests/automl_tests/test_iterative_algorithm.py	100.0% <100.0%> (ø)

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[bchen1116]

Nice, glad the fix was fairly quick! Can you update the docs here and (maybe?)here and remove the list support/examples? Not sure if you need to remove the second one, but for sure the first

[angela97lin]

@bchen1116 Thanks for pointing these out, I had no idea we had doc examples of this. Removed! 🥂

[freddyaboulton]

Looks great @angela97lin !!

[freddyaboulton]

I think we should still keep a list example so that we can verify the IterativeAlgorithm now handles them properly!

[angela97lin]

@freddyaboulton Correct me if I'm misunderstanding but the idea now is that we don't support lists so they shouldn't be handled correctly / are expected to error, right? 😅

[freddyaboulton]

I'm thinking about the Drop Columns case for the data check actions. We would specify the columns to drop in the pipeline_params of the IterativeAlgorithm (at least that's the impl in #1981). So we can still pass lists it's just that the IterativeAlgorithm shouldn't do anything to that list and just pass it to the pipeline in the parameters dict.