Candidate/1.5.9

[rmigneco]

Description

Release candidate for 1.5.9

Change Notes

• Xcode 16 compiler fixes
• Bumped version numbers

Pre-submission Checklist

• [ ] I ran the unit tests locally before checking in.
• [ ] I made sure there were no compiler warnings before checking in.
• [ ] I have written useful documentation for all public code.
• [ ] I have written unit tests for this new feature.

[CLAassistant]

All committers have signed the CLA.