External Version bump for alpinelinux new version string "3.15"

roles/netbootxyz/defaults/main.yml

@@ -129,8 +129,8 @@ releases:
     mirror: http://dl-cdn.alpinelinux.org
     name: Alpine Linux
     versions:
-    - code_name: v3.14
-      name: '3.14'
+    - code_name: v3.15
+      name: '3.15'
     - code_name: edge
       name: Edge (development)
   anarchy: