Enable developer warnings in C++ CI

[scal444]

No description provided.

[greptile-apps]

Confidence Score: 5/5

The PR appears safe to merge, with no outstanding correctness, security, or repository-rule issues identified.

Summary

Enables developer warning flags in the C++ CI build and resolves the resulting warnings without changing intended runtime behavior.

• Enables NVMOLKIT_EXTRA_DEV_FLAGS in the C++ build-and-test workflow.
• Avoids a Boost.Python compiler false positive by using a named boolean extractor.
• Makes MMFF clamp-bound types explicit.
• Marks conditionally used CUDA locals as potentially unused.

_{Reviews (2) · Last reviewed commit: "Mark optional CUDA diagnostics as unused"}

[evasnow1992]

Thank you for switching on the warnings in C++ CI. Changes look good to me.