cad/openvsp: update to 3.42.3

ChangeLog: https://github.com/OpenVSP/OpenVSP/releases/tag/OpenVSP_3.42.3

Fixes:

• Fix casting of string literals to bool for NameValData.
• Fix RenameAttr in ResultsMgr enforces persistent AttrID.
• Attributes API revisions.
• Cleanup AttributeExplorer construction.
• Link pthread library to cartesian example on linux.
• Correctly delegate constructor for NVD bool case.