Update changelog for v3.23.1 release
## Unreleased
+## 3.23.1 (December 19, 2022)
+
- Add `PULUMI_K8S_ENABLE_PATCH_FORCE` env var support (https://github.com/pulumi/pulumi-kubernetes/pulls/2260)
- Add link to resolution guide for SSA conflicts (https://github.com/pulumi/pulumi-kubernetes/pulls/2265)
- Always set a field manager name to avoid conflicts in Client-Side Apply mode (https://github.com/pulumi/pulumi-kubernetes/pulls/2271)
