Irrepealable tax to repay debt of municipality or political subdivision.
county, town, school district or any other subdivision incurring indebtedness shall, at or before
the time of so doing, provide for the collection of an annual tax sufficient to pay the interest and
also the principal thereof when due, and all laws or ordinances providing for the payment of the
interest or principal of any debt shall be irrepealable until such debt be paid.