CLN: avoid catching AssertionError, AttributeError in NDFrame methods
@WillAyd when i run `mypy` manually it passes, but when run via the pre-commit hook I get

```
pandas/core/internals/blocks.py:2739: error: unused 'type: ignore' comment
pandas/core/generic.py:4034: error: unused 'type: ignore' comment
pandas/core/generic.py:4093: error: unused 'type: ignore' comment
Found 3 errors in 2 files (checked 2 source files)
```

Something similar is happening with most branches these days.  Have you seen this?
looks ok, needs a rebase updated+green I think @xhochy has some experience with that pre-commit / mypy issue