- HTTP/2 connection health check is enabled by default in all Kubernetes clients. The feature should work out-of-the-box. If needed, users can tune the feature via the HTTP2_READ_IDLE_TIMEOUT_SECONDS and HTTP2_PING_TIMEOUT_SECONDS environment variables. The feature is disabled if HTTP2_READ_IDLE_TIMEOUT_SECONDS is set to 0. ([#95981](https://github.com/kubernetes/kubernetes/pull/95981), [@caesarxuchao](https://github.com/caesarxuchao)) [SIG API Machinery, CLI,...

* Fixes API compatibility issue with empty lists incorrectly returning a null `items` field instead of an empty array. ([#39834](https://github.com/kubernetes/kubernetes/pull/39834), [@liggitt](https://github.com/liggitt))
* Re-add /healthz/ping handler in genericapiserver ([#38603](https://github.com/kubernetes/kubernetes/pull/38603), [@sttts](https://github.com/sttts))

connection health check is enabled by default in all Kubernetes clients to fix persistently broken connections (https://github.com/kubernetes/client-go/issues/374). If needed, users can tune the feature via the HTTP2_READ_IDLE_TIMEOUT_SECONDS and HTTP2_PING_TIMEOUT_SECONDS environment variables. The feature is disabled if HTTP2_READ_IDLE_TIMEOUT_SECONDS is set to 0. ([#100376](https://github.com/kubernetes/kubernetes/pull/100376), [@liggitt](https://github.com/liggitt)) [SIG API Machinery, CLI, Cloud...