Better AI Worker handling with systemd units

[liamdennehy]

Before You Submit

• I have checked for existing issues and pull requests related to my suggestion.
• I have posted on the Nextcloud Community Help Forum if my suggestion is a troubleshooting scenario or I'm unsure about the solution.

Type of Suggestion

Suggesting an improvement

Relevant Documentation Links

https://docs.nextcloud.com/server/latest/admin_manual/ai/

Summary

Improve the systemd unit file creatin and handling for AI workers.

Details

Improved and systemd-native way of running AI workers:

• avoiding the need for shell scripts and sudo
• Invoke systemctl commands without for loops

Full description in #15509

Additional Notes

No response