[develop] Fix a bug that was causing compute node self‑termination to hang on Ubuntu 24.04 nodes

[hehe7318]

Description of changes

• Detect OS before run the self-termination command
• If the OS is ubuntu2404, run systemctl poweroff --force instead of shutdown -h now

Tests

• I created a AL2 and Ubuntu2404 cluster to manually test. Test ongoing, will update the result later

Checklist

• Make sure you are pointing to the right branch.
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• Make sure to have added unit tests or integration tests to cover the new/modified code.
• Check if documentation is impacted by this change.

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