Support GHC 9.10

[andreasabel]

Optimistic strategy: assume that nothing breaks if dependencies bump
their major version (unless they bump the major-major version).

Breakage can then be addressed by Hackage revisions.

[Bodigrim]

It would be nice to revise cabal-doctest on Hackage, otherwise plenty of packages are blocked from upgrade to GHC 9.10.

[ulidtko]

Hi @andreasabel! I've fixed the CI for GHC 9.10. We're ready for revision 4 here.

(Per #79, repo transfer was done today; I'd appreciate if you let me upload the revision myself, to get practice)

I'm happy with major-major bounds in the examples / tests — but in the main lib, I'm reverting to Cabal < 3.14. This feels more uniform, in-line with previous revisions, and I don't feel confident enough (in Cabal as a dependency) to break the pattern just yet.

[Qqwy]

Looking forward to the new version release!

[Bodigrim]

@phadej could you possibly add @ulidtko to maintainers? https://hackage.haskell.org/package/cabal-doctest/maintainers/

[andreasabel]

could you possibly add @ulidtko to maintainers? hackage.haskell.org/package/cabal-doctest/maintainers

Done!

[ulidtko]

Thanks @andreasabel 🙏

I'm going to merge this, but will actually release another version, rather than a metadata revision. Because there was a code change in 009a688 — albeit small, strictly speaking it steps beyond applicability of hackage revisions mechanism, IIUC.