Update logging package to use grpc-middleware v2.0.0-rc.3

[metalmatze]

If we update github.com/grpc-ecosystem/go-grpc-middleware/v2 to v2.0.0-rc.3 it breaks in the pkg/logging package, as the package github.com/grpc-ecosystem/go-grpc-middleware/v2/interceptors/tags doesn't exist anymore.

We should update the Thanos logging package accordingly.

cc @manojVivek for discovering this.

[avinilcodes]

@metalmatze I am willing to contribute, Can i take it up? I would have some questions here and there while understanding and in dev phase please guide accordingly. Please assign this to me

[metalmatze]

Go for it. 😊