Revert "External Version bump for alpinelinux new version string "3.22""

This reverts commit 173cfb1271327389874b72923c69f25eead8afaa.

roles/netbootxyz/defaults/main.yml

@@ -157,8 +157,8 @@ releases:
     mirror: http://dl-cdn.alpinelinux.org
     name: Alpine Linux
     versions:
-    - code_name: v3.22
-      name: '3.22'
+    - code_name: v3.21
+      name: '3.21'
     - code_name: edge
       name: Edge (development)
   archlinux: