go-kit
chore: update golang-jwt/jwt and other modules
This PR updates all go modules to the latest version.
The main changes are related to golang-jwt/jwt v5, for which I followed the migration guide.
The only breaking change I'm introducing in go kit is the rename of StandardClaimsFactory() into RegisteredClaimsFactory() in order to keep consistency with the underlying naming.
A major version bump signals backwards-incompatible changes, essentially an entirely different module than the previous major version. If you want to use jwt/v5 then I'd like to see it either as a new Go kit "jwt2" package, or a pretty comprehensive test suite to ensure that "mostly backwards compatible" actually means "fully backwards compatible" in terms of the API that Go kit offers to its consumers.
