gh-37894: sagemath-standard: some fixes in build dependencies
- [build-system] requires: neither jupyter_core nor ppl are needed to
build sagemath-standard.
- networkx: remove upper bound since 3.3 works just fine.
### :memo: Checklist
<!-- Put an `x` in all the boxes that apply. -->
- [x] The title is concise and informative.
- [x] The description explains in detail what this PR is about.
URL: https://github.com/sagemath/sage/pull/37894
Reported by: Gonzalo Tornaría
Reviewer(s): Dima Pasechnik
