Fix dev/core#4971 - Skip redundant permission checks in CRM_Admin_Form_ScheduleReminders

Fix dev/core#4971 - Skip redundant permission checks in CRM_Admin_Form_ScheduleReminders

Temporary override to solve https://lab.civicrm.org/dev/core/-/issues/4971
This regressed in https://github.com/civicrm/civicrm-core/pull/27003 which
switched $this->retrieveMethod to 'api' - this had the unintended effect of checking
permissions during retrieveValues(), but the API is not sophisticated enough: we need to
add
a `CRM_Core_BAO_ActionSchedule::addSelectWhereClause()` function that can handle the logic
of "if the reminder is for an event, check user has edit permission for that specific
event".

Meanwhile we can skip permission checks in the form layer, because that logic is
implemented here,
specifically in `\CRM_Event_ActionMapping::checkAccess()`.