Stop advertising adding wheel as an unconditional PEP 517 build dependency

[webknjaz]

It's already pulled in by setuptools automatically, when building wheels is requested from the frontend. If only sdists are being build, pyproject.toml shouldn't forcefully inject this dependency into the ephemeral build env.

This has mostly been cleaned up from other places in the ecosystem and should be done here as well.

Related PRs:

• Stop injecting wheel as a build dep fallback build#716
• Stop injecting wheel as a build dep fallback pip#12449
• Stop mentioning wheel in the context of PEP 517 setuptools#3056

Action items:

• Find all the pyproject.toml files that have setuptools in their [build-system].requires
• Delete wheel from the lists where it's also present

[pfmoore]

Find all the pyproject.toml files that have setuptools in their [build-system].requires

That sounds more complex than I think you mean - isn't it just the following one line?

https://github.com/pypa/sampleproject/blob/main/pyproject.toml#L153

[webknjaz]

You're right. I think there was some other repo under @pypa that has multiple project examples in it that I confused this one with.

[webknjaz]

I was thinking of https://github.com/pypa/sample-namespace-packages, it seems.

[chrysle]

#204 addresses this.

[webknjaz]

@chrysle as I said above — I originally thought of a different repo. Also, that PR does too much stuff than just removing 9 bytes from a single place, which would've been much cleaner.

[chrysle]

I guess this can be closed, nevertheless? What's done is done.