* Remove all previous capabilities checks.
* Bump version from 3.0.1-rc6 to 4.0.0-rc1.
* Add new flag global.cattle.psp.enabled to control installation of PodSecurityPolicies.
* Add new validate-psp-install.yaml file to check whether PSPs can be installed.
* Update app-readme.md with PSP notice.
* Bump Kubernetes compatibility versions to < 1.26.0.