- Removed GA'ed feature gate `DelegateFSGroupToCSIDriver`. ([#117655](https://github.com/kubernetes/kubernetes/pull/117655), [@carlory](https://github.com/carlory))
- Removed GA'ed feature gate `DevicePlugins`. ([#117656](https://github.com/kubernetes/kubernetes/pull/117656), [@carlory](https://github.com/carlory))

- Removed `GA`ed feature gate `TopologyManager`. ([#121252](https://github.com/kubernetes/kubernetes/pull/121252), [@tukwila](https://github.com/tukwila))
- Removed `GA`ed feature gates `OpenAPIV3`. ([#121255](https://github.com/kubernetes/kubernetes/pull/121255), [@tukwila](https://github.com/tukwila))

- Refactor kubelet command line for enabling features and "drop `RuntimeClass` feature gate" if present. Note that this feature has been on by default since 1.14 and was GA'ed in 1.20. ([#106882](https://github.com/kubernetes/kubernetes/pull/106882), [@cyclinder](https://github.com/cyclinder))

In 1.20, we introduce a new alpha feature `CSIServiceAccountToken`. This feature allows CSI drivers to impersonate the pods that they mount the volumes for. This improves the security posture in the mounting process where the volumes are ACL’ed on the pods’ service account without handing out unnecessary permissions to the CSI drivers’ service account. This feature is especially important for secret-handling CSI drivers, such as the secrets-store-csi-driver. Since these tokens can be rotated...