testing/cri-o: security upgrade to 1.26.2

• Add apparmor build tag.
• Move contrib CNI plugins to examples directory (in -doc subpackage). See https://github.com/cri-o/cri-o/tree/main/contrib/cni#readme
• Use oci-runtime instead of runc
• Remove conmon dependency, so it is optional

The rationale behind the removal of runc and conmon is:

• cri-o can work with any OCI-compatible runtimes, e.g youki, crun. This can be configured inside cri-o's configuration file.
• For conmon, there is a new project conmon-rs that is trying to be a re-implementation in Rust. It still lacks features but is usable with cri-o. See https://github.com/containers/conmon-rs/blob/main/usage.md