Update pyvista version requirement to >=0.46

[thomashampson]

I think this helps pixi avoid installing an incompatible vtk version.

To test:

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[jclarkeSTFC]

Package build

[jclarkeSTFC]

Standalone builds look fine on Windows and IDAaaS

[peterfpeterson]

I'm currently running pyvista 0.46.4 and vtk-base 9.3.1 through pixi. This can be seen in the active pixi.lock.

[jclarkeSTFC]

I'm currently running pyvista 0.46.4 and vtk-base 9.3.1 through pixi. This can be seen in the active pixi.lock.

Do you get the same if you use a conda environment?

[sf1919]

Does this need re-reviewing now that we have moved our CI to pixi?

[jclarkeSTFC]

I'd suggest a rebase then we see what happens