--allow-newer/older is documented as a Cabal option, but it's a cabal-install one

[fgaz]

The docs say --allow-newer is a Cabal flag

https://cabal.readthedocs.io/en/3.4/setup-commands.html#cmdoption-runhaskell-Setup.hs-configure-allow-newer

but the flag is in ConfigExFlags, which is in cabal-install, so that part of the docs needs moving

Relatedly, we may want to move that option to Cabal, as it'd be useful for distributions. EDIT: #7445

[maralorn]

Having this in Setup.hs would be great!

Currently in nixpkgs, where we use Setup.hs for every package, we have only to option to ignore all or none of the bounds. More granularity would be great.

[fgaz]

I opened #7445 to keep track of the feature, so we can use this ticket only for the docs change

[ulysses4ever]

This has been fixed in #7861.

As for getting it back to Setup, there's a long history, which I recap in #7445.