Relax upper bound on base for GHC 9.14.1/base-4.22.0.0

[mpilgrem]

splitmix-0.1.3.1 builds with GHC 9.14.1.

[phadej]

Through a lot of hoops, this is partially blocked on

• Support GHC version 9.14.1. haskell/hsc2hs#105
• Relax upper bound on base for GHC 9.14.1/base-4.22.0.0 simonmar/async#175