Dropping support for Python 3.9 due to critical vulnerability with a dependency

[shachafl]

We have kept support for Python 3.9 beyond its recommended life span although it was dropped by the scientific community in April 2024 (https://numpy.org/neps/nep-0029-deprecation_policy.html).
A critical vulnerability in Dask <= 2024.8.2 forces us to drop Python 3.9 as Dask dropped support for Python 3.9 in version 2024.8.1.
After this change we will still have at least 3 working versions of Python (3.10-12).

Subtasks:

• Remove python 3.9 in automatic tests (.github/workflows/starfish-prod-ci.yml)
• Update 4 requirements files
• Bump python version to 3.10 in docker/Dockerfile
• Update docs (README.rst & docs/source/installation/index.rst)
• Update comments in examples/quick_start/plot_quick_start.py
• Remove Python 3.9 in packaging files (pyproject.toml)
• Make new release