* cmd/k8s-operator: generate static manifests from Helm charts
This is done to ensure that there is a single source of truth
for the operator kube manifests.
Also adds linux node selector to the static manifests as
this was added as a default to the Helm chart.
Static manifests can now be generated by running
`go generate tailscale.com/cmd/k8s-operator`.
Updates tailscale/tailscale#9222
Signed-off-by: Irbe Krumina <irbe@tailscale.com>
