Bump dependencies for NumPy 2 compatibility

[cbrnr]

All tests pass and demo.ipynb works without any errors or warnings using NumPy >= 2.

[cbrnr]

OK, I'm struggling a bit with dependencies here. If you want to keep Python >= 3.9 and at the same time also support 3.13, scipy >= 1.13.1 works only for Python <= 3.12. Strangely, uv does not use scipy 1.14.1 (there is no binary wheel for scipy 1.13.1 for Python 3.13) for Python 3.13, but insists on using 1.13.1...

[bemoody]

Sure, seems like the problem is that "uv run --extra dev pytest" is doing something bizarre.

I don't know exactly what that command is doing or trying to do, but it seems to be trying to install the oldest versions of packages that satisfy our dependencies. That is not what we want (that's not what any normal user does) and is not likely to lead to a good solution.

[cbrnr]

It might actually be something at the core of how uv resolves dependencies, yes. I've opened an issue here: astral-sh/uv#8492

[YmirKhang]

Hells yeah!

[cbrnr]

Hmmm, the Windows 3.13 job crashed, but this might be unrelated. @bemoody or @tompollard could you please restart this job (I don't have the permissions to do that myself)?

[cbrnr]

We're hitting another issue, this time related to CPython (python/cpython#125235). We gotta wait for 3.13.1 for the fix.

[cbrnr]

This is ready for review. Everything works with NumPy >= 2. I've removed support for Python 3.8 and added Python 3.12. Python 3.13 can be added as soon as 3.13.1 is released, but I would do that in a separate PR. It would be great if you could push out a new release to PyPI once this PR gets merged.

[cbrnr]

OK, I'd really appreciate if someone took a look. I've now enabled weak_and_warn, and the Python 3.9 job on Ubuntu uses numpy==1.26.4 (all other jobs use numpy>=2). One test fails, which I cannot reproduce locally (neither on macOS nor on Linux).

The Windows jobs all emit a warning related to tk (see here), but I think these warnings have always been there (not a result of this PR).

Another question that came up: is the Debian i386 job still needed? It runs the tests with Python 3.7, which is not supported anymore.

Finally, and this is a question for when all other issues have been resolved, the test matrix is rather large. Is it really necessary to test on all combinations of OSs and Python versions?