chore: update pyproject.toml to remove python 3.11 and add python 3.14

[zmx27]

Closes#74

[zmx27]

@sbillinge ready for review

Edit: It seems like tests are failing because pyobjcryst does not support python 3.14. Should we start porting pyobjcryst to 3.14 as well, or should I pin the python version in tests-on-pr.yml to 3.13 for now so tests can pass?

[sbillinge]

pyobjcryst needs to be ported. I htink @cadenmyers13 is working on that. @cadenmyers13 ?

[cadenmyers13]

@sbillinge@zmx27 Yeah that is the case. pyobjcryst needs to support 3.14 before srreal can

[zmx27]

Does this mean that I should work on pyobjcryst before srreal? I don't see a "Ready for ... Release" Issue yet, but I do see two issues attached to this release milestone:
https://github.com/diffpy/pyobjcryst/milestone/1

Or do we simply want to change the python version for the tests to 3.13 so that tests aren't failing in the PRs to srreal?

[cadenmyers13]

@zmx27 I am working on pyobjcryst right now so no need to do that. Focus on the other issues on srreal and leave this PR open for now. Then, when the other issues are closed, hopefully we'll have pyobjcryst up to 3.14 and this test will pass.

TLDR, ignore this issue for now and focus on the others 👍