Nit: relocate key in YAML, update comment

Author: aramprice

ci/pipelines/vars.yml

@@ -6,6 +6,7 @@ stemcell_details:
   os_version: "24.04"
   os_name: ubuntu-noble
   os_short_name: noble
+  subnet_int: "24" #! use last two digits of release year: ex 2010 -> 10
   use_efi: true
   include_iaas: [
     {iaas: alicloud, hypervisor: kvm},
@@ -17,7 +18,6 @@ stemcell_details:
     {iaas: warden, hypervisor: boshlite}
   ]
   include_fips_iaas: []
-  subnet_int: "24" #! use last two digits of release year: ex 2000 -> 20
 
 blobstore_types:
 - dav