Restored 2.3 top nav link

Author: jeff-matthews

src/_data/main-nav.yml

@@ -67,6 +67,11 @@
 
     - label: Software Update Guide
       url: https://experienceleague.adobe.com/docs/commerce-operations/upgrade-guide/overview.html
+      exclude_versions: ["2.3"]
+
+    - label: Software Update Guide
+      url: /comp-mgr/bk-compman-upgrade-guide.html
+      exclude_versions: ["2.4"]
 
     - label: Configuration Guide
       url: /config-guide/bk-config-guide.html