TST: skips in extension.test_categorical
- [x] closes #38904  
- [x] Ensure all linting tests pass, see [here](https://pandas.pydata.org/pandas-docs/dev/development/contributing.html#code-standards) for how to run them

cc @simonjayhawkins 

For the searchsorted test, the categorical data starts off ordered as "C" < "A" < "B" but then gets reordered in the test by these lines:

> b, c, a = data_for_sorting
        arr = type(data_for_sorting)._from_sequence([a, b, c])

so the ordering becomes "A" < "B" < "C". This causes failure when "C" is said to be inserted at index 3 (new order) to preserve order rather than the expected 0 (original order).

