CLN: Don't catch TypeError in FrameApply.agg
- [x] tests added / passed
- [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

Ref: #34224. Back when transform and agg shared code, this was introduced to stop transform from having an infinite recursive loop. Now they do not, it is no longer necessary and only serves to obfusticate the error message.