This issue is reserved for the Data Umbrella Africa & Middle East Sprint on October 23, 2021 as a good first issue. For non-sprint contributors, please wait till October 30, 2021 to work on this issue.

Follow up to #16945

1. Make sure you have the development dependencies and documentation dependencies installed.
2. Pick an from the list below and leave a comment saying you are going to work on it. This way we can keep track of what everyone is working on.
3. Remove the estimator(s) from:

4. Run the test for checking for no validation, which should fail:

pytest sklearn/tests/test_common.py::test_estimators_do_not_raise_errors_in_init_or_set_params

5. Update the codebase so the above test passes.
6. Open a Pull Request with an opening message Addresses #21406. Note that each item should be submitted in a separate Pull Request.
7. Include the function name in the title of the pull request. For example: "ENH Removes validation in __init__ for _______".

• ColumnTransformer
• Pipeline, FeatureUnion FIX Removes validation in __init__ for Pipeline #21888
• FactorAnalysis FIX validate parameter in 'fit' for 'FactorAnalysis' #21713
• FastICA
• FeatureHasher FIX Remove validation in FeatureHasher's __init__ #21573
• GridSearchCV, HalvingGridSearchCV
• KernelDensity
• KernelPCA
• LabelBinarizer
• NuSVC, NuSVR, SVC, SVR, OneClassSVM
• RadiusNeighborsClassifier
• SGDOneClassSVM: tricky to get right (not a good first issue)
• TheilSenRegressor
• TweedieRegressor

Estimators on the same line should be fixed together since they share a parent class.