CI: categorical failures
Seeing 
```
~/work/pandas/pandas/pandas/core/indexes/base.py in get_indexer(self, target, method, limit, tolerance)
106
   3411             # potential fastpath
107
   3412             # get an indexer for unique categories then propagate to codes via take_nd
108
-> 3413             categories_indexer = self.get_indexer(target.categories)
109
   3414             indexer = algos.take_nd(categories_indexer, target.codes, fill_value=-1)
110
   3415 
111

112
RecursionError: maximum recursion depth exceeded while calling a Python object
113
<<<-------------------------------------------------------------------------
```
along with a bunch of other categorical related failures. Guessing cause may be #41934, cc @jbrockmendel 