fix: Fixes reply-to in WhatsApp Cloud API (#13467)

This change https://github.com/chatwoot/chatwoot/pull/13371 broke the
functionality. When a user replies to a WhatsApp message, the reply
context wasn't being properly stored in Chatwoot due to #13371

WhatsApp sends reply messages with a `context` field containing the
original message ID:
```json
{
    "messages": [{
      "context": {
        "from": "phone_number",
        "id": "wamid.ORIGINAL_MESSAGE_ID"
      },
      "from": "phone_number",
      "id": "wamid.REPLY_MESSAGE_ID",
      "text": { "body": "This is a reply" }
    }]
  }
```
However, the in_reply_to_external_id was being overridden when building
the message because content_attributes was explicitly set to either {
external_echo: true } or {}, which discarded the reply-to information.

.circleci/config.yml

@@ -144,7 +144,7 @@ jobs:
   # Backend tests with parallelization
   backend-tests:
     <<: *defaults
-    parallelism: 20
+    parallelism: 18
     steps:
       - checkout
       - node/install:
@@ -350,12 +350,12 @@ jobs:
           destination: coverage
 
   build:
-      <<: *defaults
-      steps:
-        - run:
-            name: Legacy build aggregator
-            command: |
-              echo "All main jobs passed; build job kept only for GitHub required check compatibility."
+    <<: *defaults
+    steps:
+      - run:
+          name: Legacy build aggregator
+          command: |
+            echo "All main jobs passed; build job kept only for GitHub required check compatibility."
 
 workflows:
   version: 2