Add package pythreejs 2.3.0 #32070
Description
(from #30123 comment:73)
https://github.com/jupyter-widgets/pythreejs
https://pypi.org/project/pythreejs/
https://github.com/jupyter-widgets/pythreejs/blob/master/pyproject.toml declares a "build-system requires" of jupyterlab~=3.0, so we may want to make it depend on the jupyterlab upgrade in #32069.
Depends on #32069
CC: @slel @jcamp0x2a @dimpase @kiwifb
Component: packages: optional
Issue created by migration from https://trac.sagemath.org/ticket/32070