CLN/TST: normalize test_frame_apply
- [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

Some minor normalizations before breaking up or parametrizing these tests
@jorisvandenbossche there's an ArrayManager test currently failing on master; any obvious candidates for something recently-merged that might account for that? @jbrockmendel @jorisvandenbossche - Just looking at recent commits, the earliest one I see failing is #40050. This failed in the PR as well. Both as well as this PR have a single test failure, `test_groupby_dtype_inference_empty`. Yes, that PR was simply merged with failing tests .. Merging master will resolve it now thanks to Brock