(B)Notwithstanding any state law, rule, or regulation to the contrary and except as may be otherwise specifically provided for in an approved charter, a charter school established and operated in accordance with the provisions of this Chapter and its approved charter and the school's officers and employees shall be exempt from all statutory mandates or other statutory requirements that are applicable to public schools and to public school officers and employees except for the following laws otherwise applicable to public schools with the same grades: ….

(20) Code of Governmental Ethics, R.S. 42:1101 et seq., with the exception of R.S. 42:1119 as it applies to any person employed by a charter school prior to August 15, 2003.