Hide plotly labels with too small font via the JS API

[physikerwelt]

https://github.com/ag-gipp/dockerAutoMscBackend/blob/37859d7730c793a43c969de030ef18a3a32f46c1/static/index.html#L140

It seems currently only possible via the python API.
cf.
https://plot.ly/javascript/pie-charts/