Minor updates to incus service files

[duskmoss]

Moving the check file to the service it actually tests, and adding opt deps for OCI containers and VM to readme and conf file.

Based on dkwo's version bump I'll update to be based on master when that lands. Will probably need some adjustments when we figure out the VM freeze thing, but wanted to open the PR for comment now.

Testing the changes

• I tested the changes in this PR: YES Locally with test instances, and running it now on my server.

Local build testing

• I built this PR locally for my native architecture, (x86-64)
• I built this PR locally for these architectures (if supported. mark crossbuilds):
  • aarch64