GH-47162: fix sample memoryMB

Author: jldohmann

modules/installation-installer-provisioned-vsphere-config-yaml.adoc

@@ -39,7 +39,7 @@ compute: <2>
     vsphere: <4>
       cpus: 2
       coresPerSocket: 2
-      memoryMB: 8196
+      memoryMB: 8192
       osDisk:
         diskSizeGB: 120
 controlPlane: <2>