Upgrade to Bevy `0.15-dev` #738

Job	Run time
nix-fmt-check	21s
nix-flake-check (ubuntu-latest)	25s
nix-flake-check (macos-latest)	1m 3s
cargo (cargo fmt --verbose --all -- --check)	1m 19s
cargo (cargo check --locked --workspace)	4m 20s
cargo (cargo check --locked --examples --workspace)	4m 56s
cargo (cargo test --locked --lib --bins --workspace --features "egui")	8m 7s
cargo (cargo doc --locked --workspace --features "egui")	7m 49s
cargo (cargo test --locked -p nannou_core --no-default-features --features "libm serde")	1m 38s
cargo (mdbook build guide/)	1m 14s
cargo (cargo test --locked -p book_tests)	7m 23s
verifications	0s
cargo-publish	0s
guide-push-to-deploy	0s
	38m 35s

Provide feedback