- Register/Deregister...

* GCE bring-up: Differentiate NODE_TAGS from NODE_INSTANCE_PREFIX ([#29141](https://github.com/kubernetes/kubernetes/pull/29141), [@zmerlynn](https://github.com/zmerlynn))
* hyperkube: fix build for 3rd party registry (again) ([#28489](https://github.com/kubernetes/kubernetes/pull/28489), [@liyimeng](https://github.com/liyimeng))

- **Overhauled metrics**: Kubernetes has previously made extensive use of a global metrics registry to register metrics to be exposed. By implementing a metrics registry, metrics are registered in more transparent means. Previously, Kubernetes metrics have been excluded from any kind of stability requirements.

  In Linux containers, this means setting the FQDN in the hostname field of the 
  kernel (the nodename field of struct utsname).  In Windows containers, this
  means setting the this means setting the registry value of hostname for the registry key HKEY_LOCAL_MACHINE\\SYSTEM\\CurrentControlSet\\Services\\Tcpip\\Parameters to FQDN. 

- Introduce alpha support for exec-based container registry credential provider plugins in the kubelet. ([#94196](https://github.com/kubernetes/kubernetes/pull/94196), [@andrewsykim](https://github.com/andrewsykim)) [SIG Node and Release]

* fix parse devicePath issue on Azure Disk ([#74499](https://github.com/kubernetes/kubernetes/pull/74499), [@andyzhangx](https://github.com/andyzhangx))
* fix Azure Container Registry anonymous repo image pull error ([#74715](https://github.com/kubernetes/kubernetes/pull/74715), [@andyzhangx](https://github.com/andyzhangx))

### TPU Enhancements

*   Adds 3D mesh support in TPU configurations ops.
*   Added TPU code for `FTRL` with `multiply_linear_by_lr`.
*   Silently adds a new file system registry at `gstpu`.
*   Support `restartType` in cloud tpu client.
*   Depend on a specific version of google-api-python-client.
*   Fixes apiclient import.

### Tracing and Debugging