A home rule unit, as defined in Article VII of the 1970 Illinois Constitution or any amendment thereto, shall have no power to change, alter, or amend in any way the provisions of this Article. A home rule unit which is a municipality, as defined in Section 4-103, shall not provide for, singly or as a part of any plan or program, by any means whatsoever, any type of retirement or annuity benefit to a firefighter other than through establishment of a fund as provided in this Article as now or hereafter amended.
40 ILCS 5/4-142