It sort-of mentioned this in the docs:
https://docs.particle.io/guide/tools-and-features/cli/photon/#update-your-device-remotely
https://docs.particle.io/reference/cli/#particle-compile
When using ‘particle compile’, it will send your files to the cloud, where they get compiled, after which you download said binary. Thus, you’re still compiling online, not locally.
As such, there are no dependencies on Arduino, and you could safely remove that should you wish to do so.