chore: Contact builder ignores custom attributes (#3571)

This is incorrect as per the documentation here: https://www.chatwoot.com/developers/api/#operation/create-a-contact
This allows setting the proper attributes when creating a contact

spec/builders/contact_builder_spec.rb

@@ -28,12 +28,14 @@ describe ::ContactBuilder do
         contact_attributes: {
           name: 'Contact',
           phone_number: '+1234567890',
-          email: 'testemail@example.com'
+          email: 'testemail@example.com',
+          custom_attributes: { test: 'test' }
         }
       ).perform
 
       expect(contact_inbox.contact.id).not_to eq(contact.id)
       expect(contact_inbox.contact.name).to eq('Contact')
+      expect(contact_inbox.contact.custom_attributes).to eq({ 'test' => 'test' })
       expect(contact_inbox.inbox_id).to eq(inbox.id)
     end