wxversion doesnt exist for wxPython 4

https://github.com/enthought/mayavi/blob/master/docs/source/mayavi/auto/wx_mayavi_embed_in_notebook.py
https://github.com/enthought/mayavi/blob/master/examples/mayavi/interactive/wx_mayavi_embed_in_notebook.py

https://wxpython.org/Phoenix/docs/html/MigrationGuide.html#the-wxversion-module

Start by comparing docs/source/mayavi/auto/wx_mayavi_embed_in_notebook.py and examples/mayavi/interactive/wx_mayavi_embed_in_notebook.py with the wxPython Phoenix Migration Guide section linked in the issue. Identify the wxversion dependency in those examples and update the affected usage for wxPython 4. Done means both notebook embedding examples work without relying on wxversion.

Written by the indexing model from the issue text.