Vulkan: Add a bounce threshold to GPUParticles to skip bouncing if the velocity is too low

[ghost]

Godot version

v4.0.alpha.custom_build [d289448]

System information

Linux, Vulkan

Issue description

The Particles are too bouncy, even on lower bounce settings, the only way to prevent this is by making them almost not bounce, which sucks.

this only happens on lower particle framerates, like 30, it's still horrible especially when it lags.

Steps to reproduce

grab particles, make them bouncy

Minimal reproduction project

TooBouncy.zip

and a video

g.mp4

(it's actually an .avi, but gitshit doesn't upload it with .avi instead of .mp4)

Fix

make a bounce threshold that makes particles stop bouncing completely when they don't bounce much anymore

example:

some particle is .01 bouncy

make it 0 bouncy