remove dependency on typing_inspect

**Is your feature request related to a problem? Please describe.**
It is lightweight, but not heavily maintained. We should be able to remove the dependency as the python API stabilizes.

I think `typing`, included in the stdlib, has most of the stuff we need, especially >3.7 (8? 9?). Specifically `get_origin`

https://github.com/ilevkivskyi/typing_inspect

**Describe the solution you'd like**
We should see what we can use in the stdlib, TBD. We should contribute back anything to python typing module that we can't do.

**Describe alternatives you've considered**
- Supporting the typing_inspect module
- Forking/including it in Hamilton

**Additional context**
Just looking through the code