Go all in on pyproject

[MicahGale]

Is your feature request related to a problem? Please describe.
Currently project meta data are stored in four files: pyproject.toml, pytest.ini, and requirements/*.txt.

Describe the solution you'd like
Consolidate all meta data into pyproject.toml. The pytest.ini consolidation should be very simple. Move all requirements information to pyproject.toml is not as simple. This would be eliminating concrete dependencies and switching to purely abstract dependencies. This is not appropriate for all projects, but for how simple the dependencies are for MontePy, this should be possible.

Additional context
Some discussions about the possibility of this transition:

• github discussion
• Official guidance on dependencies vs. requirements
• Official discussion of concrete vs. abstract

This would require updating CI/CD because pip install -r will need to be removed.

TODO list:

• move over pytest
• Move over dependencies