support numpy v2

[casperdcl]

• numpy>=2 was released on 16 June 2024
• numpy>=2.1.0 was released on 18 Aug 2024 and supports py3.13
• numpy<2 ended support on 16 Sep 2025

From migration guide:

np._set_promotion_state("weak_and_warn")

[Optionally,] use warnings.simplefilter to raise it as an error for a traceback [...]
Unfortunately, running this may flag many changes that are irrelevant in practice.

related

• numpy.core deprecated #1839
• TIFF compression unit tests fail with numpy v2 as numpy float32 can't be dumped to json #2030
• Loosen the version constraint on CIL's dependencies #2034
• Create environment files for installation #2090
• numpy version constraint #2092
• show_geometry fails with numpy2 #2242
• https://numpy.org/devdocs/numpy_2_0_migration_guide.html#changes-to-numpy-data-type-promotion
• https://numpy.org/neps/nep-0050-scalar-promotion.html#nep50

[lauramurgatroyd]

Mantid Imaging use the 'ruff' code linter
This can be used to flag numpy 2 deprecations
Potentially could just run ruff with the numpy rule