* feat: add preflight admission readiness check before kubeadm upgrade
- linked to issue #13139
- Add opt-in dry-run Job probe to verify the admission pipeline is ready before running kubeadm upgrade apply (workaround for Kubernetes #124237)
- Gate the check behind kubeadm_upgrade_preflight_check_enabled (default false) with configurable retries and delay
- Emit a warning instead of failing if the preflight check does not pass
* fix: refine preflight admission check Job and warning
- Use generateName for the dry-run preflight Job to avoid fixed-name collisions
- Expand the Kubernetes issue reference in the warning to a full GitHub URL
Created with AI-assistance
- This enables ithe override of the tolerations for the cilium-operator deployment
- default behaviour is to leave the toleration as is unless the var is set