Review JIT/GIL notes after Py3.15 release

[Robadob]

pando-python/episodes/optimisation-use-latest.md

Line 30 in 98d9d41

Future proposals, such as changes to the [JIT](https://tonybaloney.github.io/posts/python-gets-a-jit.html) and [GIL](https://peps.python.org/pep-0703/) will provide further improvements to performance.