fix: Replace CNAME with A records to allow MX records for sam2-saas-prod

- DNS specification prevents CNAME and MX records coexisting
- Replace CNAME with A records pointing to AWS ELB IP addresses
- Fix MX record format to include priority and hostname
- Resolves DNS validation failures in open-domains CI

domains/sam2-saas-prod.is-not-a.dev.json

@@ -7,12 +7,12 @@
     "email": "chibuezeogbuji01@gmail.com"
   },
   "record": {
-    "CNAME": "a50df0d491cd74be0a95d0fbc5535687-50644910.us-east-1.elb.amazonaws.com",
+    "A": [
+      "34.197.177.20",
+      "54.204.75.7"
+    ],
     "MX": [
-      {
-        "priority": 10,
-        "value": "feedback-smtp.us-east-1.amazonses.com"
-      }
+      "10 feedback-smtp.us-east-1.amazonses.com"
     ],
     "TXT": [
       "v=spf1 include:amazonses.com ~all",