FR: K8s Operator - allow setting TS_DEBUG_PRETENDPOINTS

### What are you trying to do?

Hi, following up on https://github.com/tailscale/tailscale/pull/12882:
> the new TS_DEBUG_PRETENDPOINTS env var has been tested and seems like a good solution for getting direct connections if you are on EKS and willing to use an NLB.

Can we support this configuration from the `k8s-operator`?

### How should we solve this?

It would be great to be able to set this value from an annotation so the `k8s-operator` could pick it up automatically.

### What is the impact of not solving this?

We can't use this feature when the tailscale nodes on EKS are managed by the `k8s-operator`.

### Anything else?

I'm happy to provide a PR with this feature. Thanks!