Add to the matrix Python==3.12, numpy==1.26.4

[pberkes]

Fix #217

Fingers crossed

[otizonaizit]

Great! Where did you learn the trick with specifying the version with *? This is cool, especially because we are already forward compatible with the breaking release of NumPy 3.0 scheduled for the next century :-)))

[pberkes]

uh idk it's usually used to allow for bugfix releases as in numpy==2.1.*