- Update the PYTHON_VERSION environment variable in the ci.yaml workflow file to 3.11.
- This change is necessary to ensure that the correct version of Python is used in the CI pipeline.

Makefile: update Python version in setup

- Update the Python version in the setup target of the Makefile to 3.11.
- This change ensures that the correct version of Python is used when creating the virtual environment and installing dependencies.
- It aligns with the updated PYTHON_VERSION in the ci.yaml workflow file.