Issue Description

In #1880, questions were raised regarding the maintainability of the example build backend dependencies. Specifically:

• how to handle backends that recommend upper bounds on the backend version (while tools that create per-package build environments can handle those without issue, they are a potential problem for build systems that aim to create unified build environments, such as those for Linux distros and from-source stack building projects like fromager)
• how to ensure we're not recommending excessively outdated versions of the backends

Some flavour of automation could help with the latter problem, but the former problem is a trickier one.

Code of Conduct

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