Remove sigs.k8s.io/controller-runtime dependency from */api modules

[ash2k]

Hi! My project depends on these Flux modules:

	github.com/fluxcd/notification-controller/api v1.2.4
	github.com/fluxcd/pkg/apis/meta v1.3.0
	github.com/fluxcd/source-controller/api v1.2.4

The api ones have a dependency on the sigs.k8s.io/controller-runtime/pkg/scheme package. It brings in a lot of things I don't need an don't use. Would be nice if the api modules were even lighter, without the controller-runtime module. Thank you.

[stefanprodan]

We can't do this, our APIs are generated with controller-runtime which adds scheme.