Bump Bevy to 0.15.0-rc.3.

[andriyDev]

This isn't exactly a finished product. Namely, I'm using a git dependency (dimforge/bevy_rapier#595) to get Rapier to compile. But at least we have a PR ready to go once the dependencies are published. For now, this lets me (or other users) use this as as git dependency to migrate early.

[TotalKrill]

Perfect! however I had a 0.15 branch already going, but it did not take into account the rapier examples, so this might be better to use :)

This is more complete though. However, I would like to release this crate earlier than the rapier crate, unless the rapier crate is also ready very soon when 0.15 releases

[ThierryBerger]

Hey ; bevy_rapier has a few (dev-)dependencies which might delay its release (bevy inspector egui and bevy_egui) ; as well as a will to integrate a bevy_picking backend, which is not ready yet, so it's fair to assume a bit of delay for a bevy_rapier release targeting bevy 0.15.

[andriyDev]

@TotalKrill, I don't have a strong opinion here. We could just merge this and then comment out the rapier dev dependency. I don't think we need the example to compile to release.

I can also just disable the dependency in this PR, let me know what you'd prefer!

[TotalKrill]

Lets just comment out the rapier dev for now, looking at the deplist of rapier, and what other bevy stuff it is depending on, it could be a bit of a wait.

This way we get this crate uptodate quickly, which can help the precious projects that depend on it, and as soon as rapier is out, I just cut a patch release