fix: Avoid double notification email after importing contacts (#13150)

Eliminate the second email notification sent to the account admins after processing the contacts import.

Co-authored-by: Pranav <pranav@chatwoot.com>

app/jobs/data_import_job.rb

@@ -65,7 +65,6 @@ class DataImportJob < ApplicationJob
 
     @data_import.failed_records.attach(io: StringIO.new(csv_data), filename: "#{Time.zone.today.strftime('%Y%m%d')}_contacts.csv",
                                        content_type: 'text/csv')
-    send_import_notification_to_admin
   end
 
   def generate_csv_data(rejected_contacts)