3.3.1

CRPropa 3.3.1

Bug fixes:

• Double free error can now be prevented by handing over stack objects as reference to ref_ptr<Obj> instead as pointer
• Fixed solving issues when attempting to install matplotlib==3.11.0, python==3.14.6, and crpropa==3.3 together
• Fix for the particle mass table loading leading to unknown particles

Removed features

• Removed Clock.h (can be replaced with std::chrono::high_resolution_clock from chrono.h)
• Removed AssocVector.h (can be replaced with std::unordered_map from unordered_map.h)