Backport of CNI: use check command when restoring from restart into release/1.9.x

[hc-github-team-nomad-core]

Backport

This PR is auto-generated from #24658 to be assessed for backporting due to the inclusion of the label backport/1.9.x.

The below text is copied from the body of the original PR.

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When the Nomad client restarts and restores allocations, the network namespace for an allocation may exist but no longer be correctly configured. For example, if the host is rebooted and the task was a Docker task using a pause container, the network namespace may be recreated by the docker daemon.

When we restore an allocation, use the CNI "check" command to verify that any existing network namespace matches the expected configuration. This requires CNI plugins of at least version 1.2.0 to avoid a bug in older plugin versions that would cause the check to fail. So we check the plugin fingerprint before performing the check.

If the check fails, destroy the network namespace and try to recreate it from scratch once. If that fails in the second pass, fail the restore so that the allocation can be recreated (rather than silently having networking fail).

This should fix the gap left #24650 for Docker task drivers and any other drivers with the MustInitiateNetwork capability.

Fixes: #24292
Ref: #24650
Ref: https://hashicorp.atlassian.net/browse/NET-11869

Testing & Reproduction steps

Run a cluster on a set of VMs, with at least one client. This can't be a server+client because we need to reboot the hosts. You should probably set the server.heartbeat_grace = "5m" to give yourself time to work.

• Run a Docker task with network.mode = "bridge". Wait for it to be healthy.
• Restart the agent.
• Make sure the alloc is untouched and networking works.
• Reboot the client host.
• Make sure the alloc is restored, the tasks are restarted, and networking works.

Contributor Checklist

• Changelog Entry If this PR changes user-facing behavior, please generate and add a
  changelog entry using the make cl command.
• Testing Please add tests to cover any new functionality or to demonstrate bug fixes and
  ensure regressions will be caught.
• Documentation If the change impacts user-facing functionality such as the CLI, API, UI,
  and job configuration, please update the Nomad website documentation to reflect this. Refer to
  the website README for docs guidelines. Please also consider whether the
  change requires notes within the upgrade guide.

Reviewer Checklist

• Backport Labels Please add the correct backport labels as described by the internal
  backporting document.
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  in the majority of situations. The main exceptions are long-lived feature branches or merges where
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  within the public repository.

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Overview of commits

• 08a6f87