Drop support for Swift 5

[0xTim]

JWTKit v5 should only support Swift 6

[adam-fowler]

Why?

[Joannis]

I don't see the benefit of going Swift 6+. It would definitely be painful for many of my current clients.

[0xTim]

It's causing issues trying to write some that produces no warnings/errors in both language versions. Higher up the list is we're going to move to Swift Testing which pretty much necessitates the need for Swift 6

[adam-fowler]

Last time I checked jwt-kit compiles in both 5.10 and 6.0 mode without issue.

[JaapWijnen]

Ah this is unfortunate. We're still stuck on an older swift toolchain and therefore can't use v5 of this package now anymore. We were hoping to get around issues we were having with v4. The betas were working very well before.

[0xTim]

This was mainly necessitated by the move to Swift Testing unfotunately