Jupyter crashes when using PyPlot and Julia 1.12

Just upgraded a collection of notebooks from PyPlot to PythonPlot. This stopped chronic kernel deaths and eliminated the need (I think) for running single threaded.

There were very few things I had to change and the only downside is the nagging from CondaPkg and the occasional

SYSTEM: caught exception of type :MethodError while trying to print a failed Task notice; giving up

which apparently can safely be ignored.