During work on GeometrySet import it was discovered that periodic
(cyclic) bezier curves do not need their first control point repeated
in the actual scene description.
The USD API documentation was a bit unclear on this aspect but this has
been confirmed informally on the AOUSD forum and emperically using
another implementation.
This patch removes the duplicated start point during export.
Pull Request: https://projects.blender.org/blender/blender/pulls/119185
e07081e15b