Improve cluster requirements page's OS requirements

https://docs.kubermatic.com/kubermatic/v2.22/architecture/requirements/cluster-requirements/ is kind of a confusing page. It lists OS requirements for the nodes in master clusters - Why? KKP should run on any Kubernetes cluster, we do not interact with the underlying node. IMHO this should be removed.

Seed clusters are not mentioned at all, but they should. We should also point out additional resource requirements with MLA.

The user cluster requirements are also very unclear. Why give a list of OSes here? We only allow deploying with specifics OSes, but that is documented in https://docs.kubermatic.com/kubermatic/v2.22/architecture/compatibility/os-support-matrix/. This section should only link to that, at best. Giving resource requirements for user clusters is also weird, we should just mention that node sizing shouldn't be under a certain threshold. But KKP doesn't really require any specific set of resources in a user cluster, most of the deployed system components are DaemonSets.

This page should also mention KubeOne as the recommended installer IMHO.

Start with the cluster requirements page linked in the issue, then compare its user-cluster OS section with the OS support matrix and review the missing seed-cluster and MLA context. Trace the page source in the kubermatic/docs repository and check nearby architecture pages for the KubeOne recommendation. Done means the page accurately covers master, seed, and user-cluster requirements without duplicating the support matrix.