chore: Sync pre-chat fields after custom attribute destroy (#4456)

app/jobs/inboxes/sync_widget_pre_chat_custom_fields_job.rb

@@ -0,0 +1,11 @@
+class Inboxes::SyncWidgetPreChatCustomFieldsJob < ApplicationJob
+  queue_as :default
+
+  def perform(account, field_name)
+    account.web_widgets.all.find_each do |web_widget|
+      pre_chat_fields = web_widget.pre_chat_form_options['pre_chat_fields']
+      web_widget.pre_chat_form_options['pre_chat_fields'] = pre_chat_fields.reject { |field| field['name'] == field_name }
+      web_widget.save!
+    end
+  end
+end