Minimum Python bumped to 3.11

The minimum required Python version has been increased from 3.9 to 3.11. This change is necessary because the dependency tree, including packages like onnxruntime and transformers, actually requires Python 3.10 or newer. The previous minimum was insufficient due to issues encountered when running on macOS with system Python 3.9.6. The error messages and requirements header have been updated to reflect this change.

• Bump minimum Python from 3.9 to 3.11

• Dependencies require Python 3.10+

• Update error messages and requirements header