Remove unusable sitemap endpoint

It calls a data model method which is extremely slow and heavy, and it isn't even used anyway

endpoints/web.py

@@ -332,15 +332,6 @@ def robots():
   return robots_txt
 
 
-@web.route('/sitemap.xml', methods=['GET'])
-def sitemap():
-  popular_repo_tuples = model.repository.list_popular_public_repos(50, timedelta(weeks=1))
-  xml = make_response(render_template('sitemap.xml', public_repos=popular_repo_tuples,
-                                      baseurl=get_app_url()))
-  xml.headers['Content-Type'] = 'application/xml'
-  return xml
-
-
 @web.route('/buildlogs/<build_uuid>', methods=['GET'])
 @route_show_if(features.BUILD_SUPPORT)
 @process_auth_or_cookie