fix: Do not allow sending messages if merged contact has a duplicate session (#11152)

In this PR https://github.com/chatwoot/chatwoot/pull/11139, if there is
an attempt to create a duplication session for the contact in the same
inbox, we will anonymize the old session.

This PR would prevent sending messages to the older sessions. The
support agents will have to create a new conversation to continue
messages with customer.

app/javascript/dashboard/components-next/NewConversation/helpers/composeConversationHelper.js

@@ -25,6 +25,11 @@ export const generateLabelForContactableInboxesList = ({
     channelType === INBOX_TYPES.TWILIO ||
     channelType === INBOX_TYPES.WHATSAPP
   ) {
+    // Handled separately for Twilio Inbox where phone number is  not mandatory.
+    // You can send message to a contact with Messaging Service Id.
+    if (!phoneNumber) {
+      return name;
+    }
     return `${name} (${phoneNumber})`;
   }
   return name;