update Plotly.js to version 3.0.0

The test for the pointcloud trace type is removed, because this
type was deprecated and has been removed in Plotly.js 3.0.0.

Author: striezel

changelog.md

@@ -12,6 +12,13 @@ version change in this application.
 
 ## Version NEXT (2025-02-??)
 
+* __[breaking change]__ + __[maintenance]__
+The version of Plotly.js is bumped from 2.35.3 to 3.0.0.
+The new version contains some new features and fixes. It also contains some
+breaking changes, for example some deprecated features have been removed. For
+details on those see
+[the changelog of Plotly.js](https://github.com/plotly/plotly.js/blob/master/CHANGELOG.md#300----2025-01-27).
+
 * __[maintenance]__
 Update dependencies `tldts` + `tldts-core` to 6.1.76.
 

export-server/plotly-2.35.3.min.js

@@ -75,7 +75,7 @@ exports.render = async function(jsonData, width, height) {
   };
 
   return await
-  fs.promises.readFile('./plotly-2.35.3.min.js', 'utf-8')
+  fs.promises.readFile('./plotly-3.0.0.min.js', 'utf-8')
     .then(win.eval)
     .then(() => win.Plotly.toImage({data: array_data, layout: layout, config: config},
                                    { format: 'svg', imageDataOnly: true }))