Use k8s.io/cli-runtime for kubernetes flags

cmd/flux/bootstrap_bitbucket_server.go

cmd/flux/bootstrap_git.go

cmd/flux/bootstrap_github.go

cmd/flux/bootstrap_gitlab.go

cmd/flux/check.go

cmd/flux/check_test.go

cmd/flux/completion.go

cmd/flux/create.go

cmd/flux/create_alert.go

cmd/flux/create_alertprovider.go

cmd/flux/create_helmrelease.go

cmd/flux/create_image_policy.go

cmd/flux/create_image_repository.go

cmd/flux/create_image_update.go

cmd/flux/create_kustomization.go

cmd/flux/create_receiver.go

cmd/flux/create_secret_git.go

cmd/flux/create_secret_helm.go

cmd/flux/create_secret_tls.go

cmd/flux/create_source_bucket.go