This eases the testing of fleetd updates (to `edge`) on Linux amd64
(from macOS).
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## Summary by CodeRabbit
* **Chores**
* Build process now accepts optional CLI configuration parameters
(--update-url, --orbit-channel, --desktop-channel, --osqueryd-channel)
to customize package generation during builds.
* Containerized fleetd services now use a restart policy that keeps
services running unless explicitly stopped, improving reliability and
reducing downtime.
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Useful while testing/developing #24385.
In the future we can push some of these to Fleet's Docker Hub and
include them in `fleetctl preview` to allow demoing of e.g. script
execution on linux devices.
Lucas Manuel Rodriguez