Test GHC 9.4 with bzlmod on CI

[avdv]

Is your feature request related to a problem? Please describe. We disabled GHC 9.4.x jobs for bzlmod on CI since we need to provide a version specific stack snapshot and json file.

Describe the solution you'd like Find a way to pass corresponding stack yaml and json files according to the currently active GHC version.

Ideally, this should only have an impact on our CI run, not on user's of rules_haskell.

Describe alternatives you've considered

Additional context See https://github.com/tweag/rules_haskell/pull/2005