Lockfile

For me one of the most important things about a mono repo is making sure that packages are compatible with each other by sharing a lock file between projects. Otherwise it can become intractable to do local development with different packages, run integration tests, etc. Cargo keeps a single lock file for the entire workspace. Could monas do the same thing?

From the docs:

> Monas, however, does not create any lock files. This is to ensure the installation is fast and correct. That is to say, Monas doesn’t talk with any package managers other than pip.

It's not clear to me if this is a hard technical limitation or something that could be worked around. I think it might be reasonable to only support this with `pyproject.toml`s that follow PEP 631 or something like that.