Instance count is only updated if geometry is dirty

[vorg]

cachedGeom.instances = geometry.instances;

Forcing me to do geometry spreads

psEntity.geometry.instances = particleSystem.count;
        psEntity.geometry = {
          ...psEntity.geometry,
        };

This is too error prone and the assignment of instances, count and primitive should be taken out of if (geometryDirty) check

pex-renderer/systems/geometry.js

Line 84 in 7d41f4a

cachedGeom.instances = geometry.instances;