Fix non-deterministic mesh rendering order

[emilk]

What

• Closes Non-deterministic Z-fighting (iter over hash?) #10116

Details

This is not a perfect fix, since you still get a different order each time you restart Rerun, but at least the flickering is gone.

[github-actions]

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• I have tested the web viewer

Result	Commit	Link	Manifest
✅	8020851	https://rerun.io/viewer/pr/10117	+nightly +main

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