Compatibility with optparse-applicative-0.18

[andreasabel]

• Fix build with optparse-applicative-0.18
  • https://github.com/pcapriotti/optparse-applicative/issues/481
• Bump Haskell CI to GHCs 9.6.2 9.4.5 9.2.8

[andreasabel]

@jhenahan Thanks for merging!

After rerelease, please make yourself heard at

• https://github.com/commercialhaskell/stackage/issues/6986

so that hasktags is added to stackage nightly again.

[andreasabel]

@jhenahan Could you please release to hackage?