Fixed ModelInstanceCollection test failure

[lilleyse]

Upgraded the RiggedFigure test model to glTF 2.0 and normalized the bone weights. This fixes a local test failure in ModelInstanceCollection which had the same clipping problem as #8958 (comment).

[cesium-concierge]

Thanks for the pull request @lilleyse!

• ✔️ Signed CLA found.
• ❔ CHANGES.md was not updated.
  • If this change updates the public API in any way, please add a bullet point to CHANGES.md.

Reviewers, don't forget to make sure that:

• Cesium Viewer works.
• Works in 2D/CV.
• Works (or fails gracefully) in IE11.

[lilleyse]

@baothientran can you review and merge? You can use the sandcastle in #8958 (comment) and point it to the rigged figure model to visualize the difference between this branch and master.

[baothientran]

Thanks, @lilleyse. The change fixes the issue. Here is the render in the master:

Below is the render of the fix:

[sanjeetsuhag]

@lilleyse @baothientran This test is failing locally. Worked fine in d0641b5, but afb7918 broke the test.

[baothientran]

@sanjeetsuhag it seems like the model is rendered but the height of the model is off from the center. I'm still investigating

[sanjeetsuhag]

Fixed in #9006.