Blender: Fix missing animation data when updating blend assets

[simonebarbieri]

Changelog Description

Fix missing animation data when updating blend assets.

Additional info

There was a specific case when updating assets that were published without animation. If an animation was added after them being loaded, when updating it would throw an error.

Testing notes:

1. Load an asset that is without any animation data (it must not have any animation in the outline when loaded).
   
   
2. Add an animation to that asset.
3. Try to update the asset.

[LiborBatek]

Been tested in Ayon mode and works without any issues! There arent any issues when updating, switching and setting versions of loaded assets whatsoever.

[ynbot]

Task linked: OP-8036 Blender: Fix missing animation data when updating blend assets