Tweak the depth bias multiplier for WebGL (#2491)

### What
Closes #2483

### Checklist
* [x] I have read and agree to [Contributor
Guide](https://github.com/rerun-io/rerun/blob/main/CONTRIBUTING.md) and
the [Code of
Conduct](https://github.com/rerun-io/rerun/blob/main/CODE_OF_CONDUCT.md)

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PR Build Summary: https://build.rerun.io/pr/2491

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Docs preview: https://rerun.io/preview/12ef481/docs
Examples preview: https://rerun.io/preview/12ef481/examples
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crates/re_renderer/shader/utils/depth_offset.wgsl

@@ -86,7 +86,8 @@ fn apply_depth_offset(position: Vec4, offset: f32) -> Vec4 {
     var w_scale_bias = f32eps * offset;
     if frame.device_tier == DEVICE_TIER_GLES {
         // Empirically determined, see section on GLES above.
-        w_scale_bias *= 1000.0;
+        // For `human_pose_tracking` 1000.0 is way too high, 512.0 mostly works, 64.0 is better: https://github.com/rerun-io/rerun/issues/2483
+        w_scale_bias *= 5120.0;
     }
     let w_scale = 1.0 - w_scale_bias;