Bump dependency version bounds

[voidus]

Heya,

This adjusts versions to match the ones in nixpkgs-24.11 haskellPackages, which as far as I know tracks the current stackage lts.

I looked through the changelogs and found these potential issues:

aeson:

• Change time instances of types with year (Day, UTCTime) to require years with at least 4 digits.

http-api-data:

• Use attoparsec-iso8601-1.1.0.0. Day and UTCTime parsers require at least 4 digits now, which is a breaking change.
• Drop GHC-7.8 and GHC-7.10 support.

mtl:

• Require GHC 8.6 or higher, and cabal-install 3.0 or higher.

servant-client:

• Escape special chars in QueryParams. #1584 #1597
• Escape special chars in QueryParam (:@&=+$) in servant-client. Note that this mean binary data will not work as is, and so reverts the functionality in #1432.

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Based on the mtl change, I removed the special casing for ghc <8.4

The rest should probably be fine, but I don't really know the code.