Update 3d-axes.md

Author: LiamConnors

doc/python/3d-axes.md

@@ -6,7 +6,7 @@ jupyter:
       extension: .md
       format_name: markdown
       format_version: '1.3'
-      jupytext_version: 1.14.7
+      jupytext_version: 1.15.1
   kernelspec:
     display_name: Python 3 (ipykernel)
     language: python
@@ -259,7 +259,3 @@ fig.update_layout(scene=dict(xaxis_showspikes=False,
                              yaxis_showspikes=False))
 fig.show()
 ```
-
-```python
-
-```