Improve Redux types part 4 (#26003)

* Fix return type of addUsersToChannel

* Fix type of TeamInviteWithError.error

* Change Constants.Integrations.PAGE_SIZE into a number"

webapp/channels/src/components/admin_console/system_users/system_users_dropdown/system_users_dropdown.tsx

@@ -135,7 +135,7 @@ export default class SystemUsersDropdown extends React.PureComponent<Props, Stat
         if (this.shouldDisableBotsWhenOwnerIsDeactivated()) {
             await this.props.actions.loadBots(
                 Constants.Integrations.START_PAGE_NUM,
-                parseInt(Constants.Integrations.PAGE_SIZE, 10),
+                Constants.Integrations.PAGE_SIZE,
             );
         }
         this.setState({showDeactivateMemberModal: true});