[MAINT] Replace setup.py with pyproject.toml

[adam2392]

PR Description

First part of #159

Merge checklist

Maintainer, please confirm the following before merging:

• All comments resolved
• This is not your own PR
• All CIs are happy
• PR title starts with [MRG]
• whats_new.rst is updated
• PR description includes phrase "closes <#issue-number>"

[adam2392]

Is this along the lines of what you meant? @larsoner

I can make the CIs pass for #159, so then this is just an intermediary PR to get the files swapped out and then the next PR would run the formatters in #159, which would then make the CIs pass.

[larsoner]

Yeah it would work to merge this with failing style CI then fix the style stuff in a separate PR which could then (later) be added to .git-blame-revs-ignore.

Also while you're at it we could enable pre-commit.ci and allow it to run your style checks if you want if you add a .pre-commit-config.yaml. But if that's too much for now you can do it later too

[adam2392]

Once this is good to go, I'll merge this and then proceed with the formatting in #159 and add to git-ignore.

I guess for the precommit stuff, I can just copy what MNE-Python has?

[larsoner]

I guess for the precommit stuff, I can just copy what MNE-Python has?

Yes a subset of it at least. We just added some mypy stuff you don't need for example.

Feel free to merge and continue if you're ready @adam2392 !