aeson 2.2 support

[Miezhiko]

not sure how to fix this code after aeson 2.2 changes,
current cabal limits <2.2 but for better compatibility with other things I want it to build with aeson 2.2.1
so I need little help

(.?=) :: (Aeson.ToJSON v, Aeson.KeyValue kv) => Aeson.Key -> Maybe v -> Maybe kv
k .?= Just v = Just (k Aeson..= v)
_ .?= Nothing = Nothing

(.=) :: (Aeson.ToJSON v, Aeson.KeyValue kv) => Aeson.Key -> v -> Maybe kv
k .= v = Just (k Aeson..= v)

class CalamityToJSON' a where
  toPairs :: Aeson.KeyValue kv => a -> [Maybe kv]

newtype CalamityToJSON a = CalamityToJSON a

instance CalamityToJSON' a => Aeson.ToJSON (CalamityToJSON a) where
  toJSON (CalamityToJSON x) = Aeson.object . catMaybes . toPairs $ x
  toEncoding (CalamityToJSON x) = Aeson.pairs . mconcat . catMaybes . toPairs $ x

it gives

• Expecting one more argument to ‘Aeson.KeyValue kv’
Expected a constraint,
but ‘Aeson.KeyValue kv’ has kind
‘* -> Constraint’
• In the type signature:
toPairs :: Aeson.KeyValue kv => a -> [Maybe kv]
In the class declaration for ‘CalamityToJSON'’
|
| toPairs :: Aeson.KeyValue kv => a -> [Maybe kv]

[DrewFenwick]

I directed @Miezhiko to convert Aeson.KeyValue kv to Aeson.KeyValue e kv in the functional programming discord. That seemed to fix this error.

[Miezhiko]

this change will break 2.1 compat most likely,
issue is actual on whether it's worthwhile to use CPP to maintain compatibility or whether to just drop support for aeson 2.1