- Graduated the `LegacyServiceAccountTokenTracking` feature gate to Beta. The usage of auto-generated secret-based service account token now produces warnings by default, and relevant Secrets are labeled with a last-used timestamp (label key `kubernetes.io/legacy-token-last-used`). ([#114523](https://github.com/kubernetes/kubernetes/pull/114523), [@zshihang](https://github.com/zshihang)) [SIG API Machinery and Auth]

 - The default Bootstrap Token created with `kubeadm init` v1.8 expires
 and is deleted after 24 hours by default to limit the exposure of the
 valuable credential. You can create a new Bootstrap Token with
 `kubeadm token create` or make the default token permanently valid by specifying
 `--token-ttl 0` to `kubeadm init`. The default token can later be deleted with
 `kubeadm token delete`.

  is now available as alpha (off by default). When enabled, the `legacy-service-account-token-cleaner`
  controller loop removes service account token secrets that have not been used
  in the time specified by `--legacy-service-account-token-clean-up-period` (defaulting
  to one year), **and are** referenced from the `.secrets` list of a ServiceAccount

- Updated an audit annotation key used by the `…/serviceaccounts/<name>/token` resource handler.

- `kube-controller-manager`: The `LegacyServiceAccountTokenCleanUp` feature gate is now `beta` and enabled by default. When enabled, legacy auto-generated service account token secrets are auto-labeled with a `kubernetes.io/legacy-token-invalid-since` label if the credentials have not been used in the time...

- When the alpha `LegacyServiceAccountTokenTracking` feature gate is enabled, secret-based service account tokens will have a `kubernetes.io/legacy-token-last-used` applied to them containing the date they were last used. ([#108858](https://github.com/kubernetes/kubernetes/pull/108858), [@zshihang](https://github.com/zshihang)) [SIG API Machinery, Auth and Testing]