Update mkdocs.yml

Author: gigapod

mkdocs.yml

@@ -371,7 +371,6 @@ extra_css:
 extra_javascript:
   # Enables support for MathJax
   - javascript/mathjax.js
-  # - https://polyfill.io/v3/polyfill.min.js?features=es6
   - https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js
 
   # Enables support for KaTeX