World space particles may spawn before GlobalTransform is propagated

[camblomquist]

Bevy by default randomizes the execution order of systems registered in the app. If the executor decides to run the particle_spawner_system before transform propagation, then particles spawned on the same frame the system itself is spawned will end up on the origin. It can take a few reloads of the app to see the behavior pop up.

I'm being rude by reusing the Issue I opened with an incorrect hypothesis. I thought the system was playing twice because I had two bursts with a pretty small time gap between them which looks a lot like two systems playing at the same time when their origin position shifts.