fix array manipulation for numpy 2.4

[atravitz]

Describe the bug
I'm not sure why we didn't see the deprecation warnings in the notebooks, but it looks like we're hitting this change in our example notebook tests.

example of where else this has been seen in the wild: numpy/numpy#30591.

To Reproduce
Steps to reproduce the behavior (ideally a minimally reproducible example):

Run up through "Plotting out the relative free energy results" in this cinnabar example notebook with openfe>=1.8.1 and numpy >=2.4.0.

Proposed Solution

• until the fix is released in cinnabar, pin openfe's cinnabar's feedstocks and dev envs to use numpy <2.4.0. We may want to do a repodata-patch as well, since this affects openfe versions 1.8.1, 1.9.0, 1.9.1. we should just pin in the cinnabar's feedstock
• bump the examplenotebooks CI to test against the latest openfe release. We missed this because I left us pinned to 1.8.0. (addressed in https://github.com/OpenFreeEnergy/ExampleNotebooks/pull/302/files)
• add a test in cinnabar that reproduces this behavior - ideally we would've caught this in cinnabar CI
• fix the array handling in cinnabar

[jthorton]

This was fixed in #170 I guess we just need a release now?

[jthorton]

0.6.0 is now out and this should be fixed.