Remove the go-kit dependency

[alecsammon]

This library depends on https://github.com/go-kit/kit.
It looks to only use this for this single package: https://github.com/go-kit/kit/blob/master/metrics/discard/discard.go

Although the usage of this package is safe, the go-kit library hasn't been maintained since 2023 - and is throwing some warnings in our security scanning.

Can we look at removing usage of this external library?

The proposed PR replaces it with an internal interface - but also allows configuration via a config options.

Alternatively it could maybe be dropped completely? It's only a no-op.

[timsehn]

Thanks for the contribution. @fulghum will look at this today.

[fulghum]

Thanks for the contribution @alecsammon! 🙏 Always nice to drop a dependency, especially one that is not actively maintained.