CI fails on branch 3.10 after PackageTests\NewHaddock\ImplyDependencies

[Mikolaj]

Describe the bug

CI consistently hangs (for 6h and then gets cancelled), only on 3.10 branch (so far), in test Validate windows-latest ghc-9.0.2 with the last message

PackageTests\NewHaddock\ImplyDependencies\cabal.test.hs SKIP no cabal-install (0.64s)

Affected tickets are #9685 and #9698. Example run is https://github.com/haskell/cabal/actions/runs/7745914464/job/21317820685?pr=9685

A macos job was hanging similarly in some of there runs (but in a similar point of the CI process), but after some restarts it always completed.

To Reproduce
Steps to reproduce the behavior:

Rerun CI on affected tickets. Local repro in a container not attempted.

[Mikolaj]

This test is now disabled on branch 3.10 via #9728. Since it's a single oldish GHC and nothing else is failing, this may be a fluke.