Revert "Increase CPU units for prd instance (#698)"

This reverts commit 47c205c.

Author: casthewiz

infrastructure/ecs-main/serverless.yml

@@ -44,7 +44,7 @@ custom:
     containerCpu:
       dev: '2048'
       stg: '2048'
-      prd: '8192'
+      prd: '4096'
       dotcomstg: '2048'
       dotcomprd: '4096'
     containerMemory: