[3.6] Remove 3.5 from Doc version switcher in master. (GH-22886) (#22891)

(cherry picked from commit 283f9a2)

Author: larryhastings

Doc/tools/static/switchers.js

@@ -15,7 +15,6 @@
     '3.8': '3.8',
     '3.7': '3.7',
     '3.6': '3.6',
-    '3.5': '3.5',
     '2.7': '2.7',
   };
 

Doc/tools/templates/indexsidebar.html

@@ -7,7 +7,6 @@ <h3>{% trans %}Docs by version{% endtrans %}</h3>
   <li><a href="https://docs.python.org/3.8/">{% trans %}Python 3.8 (stable){% endtrans %}</a></li>
   <li><a href="https://docs.python.org/3.7/">{% trans %}Python 3.7 (stable){% endtrans %}</a></li>
   <li><a href="https://docs.python.org/3.6/">{% trans %}Python 3.6 (security-fixes){% endtrans %}</a></li>
-  <li><a href="https://docs.python.org/3.5/">{% trans %}Python 3.5 (security-fixes){% endtrans %}</a></li>
   <li><a href="https://docs.python.org/2.7/">{% trans %}Python 2.7 (EOL){% endtrans %}</a></li>
   <li><a href="https://www.python.org/doc/versions/">{% trans %}All versions{% endtrans %}</a></li>
 </ul>