Update index.yml

Author: vhorne

articles/firewall-manager/index.yml

@@ -11,7 +11,7 @@ metadata:
   ms.topic: landing-page
   author: vhorne
   ms.author: victorh
-  ms.date: 06/30/2021
+  ms.date: 11/14/2022
 
 # linkListType: architecture | concept | deploy | download | get-started | how-to-guide | learn | overview | quickstart | reference | tutorial | whats-new