[Python][Packaging] Drop Python 3.9 support

[raulcd]

Describe the enhancement requested

Previous issue for Python 3.8: #43518
Previous issue for Python 3.7: #34788

We dropped Python 3.7 support in pyarrow 13.0 (August 2023). We dropped Python 3.8 support in pyarrow 18.0 (October 2024). If we follow the same pattern, we should be able to drop 3.9 support for pyarrow 22, since by the time of that release it should have reached end of life (2025-10, https://devguide.python.org/versions)

Component(s)

Packaging, Python

[raulcd]

Issue resolved by pull request 47478
#47478