Provide a way to specify no-build-isolation for all pypi dependencies

[traversaro]

Problem description

Events like pypa/setuptools#4910 highlight that many users are not familiar with how build-isolation works when building Python projects, and how the python build backends (like setuptools) are not pinned in any way in the lock file.

For this reason, it may be convenient to have an option to opt out of build isolation for all pypi dependencies, with the additional burden that in that case you need to manually add to the manifest all the build backends you want to use (but with the advantage that in that case the build backends used are included in the lockfile).

[baszalmstra]

Maybe we can allow setting the no-build-isolation to false to disable build isolation for all dependencies? @tdejager

[tdejager]

Sure, but in that case is should be set to true. :)

[tdejager]

And definitely possible, we just have to expose it, pretty simple I'll add the good first issue label as well.

[traversaro]

Sure, but in that case is should be set to true. :)

I totally agree with the proposal, even if technically true is a valid Python project name (see https://packaging.python.org/en/latest/specifications/name-normalization/#name-format)?

[baszalmstra]

Fortunately, TOML makes a distinction between strings and booleans. 🙂 Also normally no-build-isolation is an array, so it should be easy to distinguish.

[traversaro]

x-ref an interesting discussion on setuptools side that highlights some problems that this issue would mitigate: pypa/setuptools#4919 .