Modernise Building Process

[ericspod]

MONAI uses requirement files, a cfg file, and a setup.py file for module definition and building. Many actions use different building processes to setup the environment for testing and install MONAI rather than just using pip install monai[...].

To modernise things, MONAI should be updated with:

• Package information consolidated in the pyprojects.toml file.
• Actions updated to use pip for installation only.
• Requirements files removed in favour of different dependencies sections like in the cfg file, this should be accompanied with a script to extract dependencies from pyprojects.toml to recreate these if needed.
• Installation instructions updated to match.
• Verify these work for tutorials and bundles.

[aymuos15]

Can we also add https://docs.astral.sh/uv/ as the default guidelines here, to be coupled with pip?