cad/openvsp: Update to 3.53.0
ChangeLog:
https://openvsp.org/blogs/announcements/2026/09/25/openvsp-3-53-0-released
Features:
- Independent skinning controls (not just values) for spines
- User-defined intermediate skinning spines
- Angle Basis From Curve option for skinning
- Visualization of skinning vectors
- Convert Fuselage to Stack
Build System:
- STEPCode 0.8.1 (with some tweaks)
- libxml2 2.15.4
- GLEW 2.3.1
- Build updated to be compatible with CMake 4
Bug Fixes:
- Entities in *.vsp3 files should now have stable ordering