Separate pytest_ethereum from package or make conditionally install

[antazoey]

What feature should we add?

A way to avoid the pytest entry point for the pytest_ethereum plugin.
Right now, I am doing -p no:pytest_ethereum everywhere because of the eth-typing 5.0.0 thing, but perhaps a more minimal install of web3.py w/o the Pytest plugin would be helpful for frameworks like Ape which are using their own pytest plugin.