fix: Delete double hmac check (#12464)

## Description

When hmac identity check is enabled according to
[this](https://www.chatwoot.com/hc/user-guide/articles/1677587479-how-to-enable-identity-validation-in-chatwoot)
I found out, that it checked twice.

If `should_verify_hmac? -> true` then hmac checked in `before_action`
and we don't need to do it again later.

This perfomance related and PR fixes this.

app/controllers/api/v1/widget/contacts_controller.rb

@@ -19,7 +19,7 @@ class Api::V1::Widget::ContactsController < Api::V1::Widget::BaseController
       contact = @contact
     end
 
-    @contact_inbox.update(hmac_verified: true) if should_verify_hmac? && valid_hmac?
+    @contact_inbox.update(hmac_verified: true) if should_verify_hmac?
 
     identify_contact(contact)
   end