Wheel is not self-contained

The pygrader wheel is not self-contained, as it relies on some files to be present. These files should be moved to the wheel and accessed from it, not the local filesystem/repo. 

This is a big change, so will leave it out-of-scope for next milestone, but I want it done after that.

Full list of files:
```bash
config/grader-requirements.txt
config/mypy_type_hints_2024.ini
config/2024.pylintrc
```