Project metadata: Increase minimum Python version to say >=3.9

[amotl]

Problem

This error started happening on Python 3.8 using the new release.

 >   MultiFetcher = Callable[list[[int, int]], bytes]  # Maps [(start, end)] to bytes
E   TypeError: 'type' object is not subscriptable

.venv/lib/python3.8/site-packages/fsspec/caching.py:40: TypeError

-- https://github.com/crate/sqlalchemy-cratedb/actions/runs/14162832181/job/39698544286#step:6:556

Details

• Supports fsspec 2025.3.1 error on python 3.8 #1816.

[martindurant]

OK, I will make 2025.3.1post1 later today and yank the previous version.

[martindurant]

This is now out as 2025.3.2 (I decided "post1" was unnecessarily complicated).

[amotl]

Where this failed before, it succeeds now.
Thank you so much for the quick turnaround.