Draft: Upgrade Kubernetes to 1.25.5

[anton-johansson]

Also upgrades:

• containerd to 1.6.12
• runc to 1.1.4
• etcd to 3.5.6
• CNI plugins to 0.9.1

Known dangers:

• Data corruption issue was found in etcd v3.5.0 release that was shipped with 1.22 Kubernetes release. Please read up-to-date production recommendations for etcd. Affects etcd 3.5.0 to 3.5.2. We'll go straight to 3.5.4, so we should be fine.
• We cannot update CNI to the latest version, because flannel has been extracted to its own library: https://github.com/flannel-io/cni-plugin. Maybe we should extract both of them and make sure the binaries are in place?

TODO:

• Test properly