Disable major version upgrades on Castle DB

Author: farski

spire/templates/apps/castle.yml

@@ -444,7 +444,7 @@ Resources:
     UpdateReplacePolicy: Retain
     Properties:
       AllocatedStorage: !If [IsProduction, "400", "100"]
-      AllowMajorVersionUpgrade: true
+      AllowMajorVersionUpgrade: false
       AutoMinorVersionUpgrade: false
       BackupRetentionPeriod: 7
       CopyTagsToSnapshot: true