Remove unused Geo::BaseNotify class

ee/app/services/geo/base_notify.rb

-# frozen_string_literal: true
-
-module Geo
-  class BaseNotify
-    def notify(notify_url, content)
-      response = Gitlab::HTTP.post(notify_url,
-                                   timeout: Gitlab.config.gitlab.webhook_timeout,
-                                   body: content,
-                                   allow_local_requests: true,
-                                   headers: {
-                                     'Content-Type' => 'application/json',
-                                     'PRIVATE-TOKEN' => private_token
-                                   })
-
-      [(response.code >= 200 && response.code < 300), ActionView::Base.full_sanitizer.sanitize(response.to_s)]
-    rescue Gitlab::HTTP::Error, Errno::ECONNREFUSED => e
-      [false, ActionView::Base.full_sanitizer.sanitize(e.message)]
-    end
-
-    private
-
-    # rubocop: disable CodeReuse/ActiveRecord
-    def private_token
-      # TODO: should we ask admin user to be defined as part of configuration?
-      @private_token ||= User.find_by(admin: true).authentication_token
-    end
-    # rubocop: enable CodeReuse/ActiveRecord
-  end
-end