ci(client-python): harmonize python versions in CI files

[guzmud]

Description

Currently in the project, we have:

• multiple mentions of python 3.13 in .circleci/config.yml
• mention of python 3.12 for coverage.yml
• mention of python 3.11 for pyproject.toml and release.yml

Yet, the pyproject.toml has requires-python = ">=3.14".

Environment

1. OS: { e.g. macOS 14, Windows 11, Ubuntu 22.04, etc. }
2. Version: { e.g. 1.2.3 }
3. Other environment details:

Reproducible steps

Steps to create the smallest reproducible scenario:

1. { e.g. Run ... }
2. { e.g. Click ... }
3. { e.g. Error ... }

Expected output

Actual output

Additional information