remove pandas series mention

Author: LiamConnors

doc/python/v6-changes.md

@@ -54,7 +54,7 @@ pip install notebook --upgrade
 pip install anywidget
 ```
 
-## Processing NumPy and Pandas Series
+## Processing NumPy and NumPy-Convertible Arrays
 
 Plotly.py now takes advantage of recent changes in how Plotly.js handles typed arrays for improved performance. See the [performance page](python/performance/) for more details.