This subchapter does not apply to:
(1) a judge of a court of record;
(2) a presiding judge of a commissioners court in a county with a population of 3.3 million or more;
(3) a district attorney paid wholly by state funds or the district attorney's assistants, investigators, or other employees;
(4) a county auditor, county purchasing agent, or the auditor's or purchasing agent's assistants or other employees; or
(5) a person employed under Section 76.004, Government Code.