The action of the governing body of any county in levying, authorizing, adopting, assessing, collecting, and enforcing any excise, privilege, or license tax levied, assessed, collected, and enforced on the effective date hereof is hereby ratified, approved, validated, and confirmed, regardless of any defect which might exist in the authorization, adoption, levy, assessment, collection, or enforcement of any such tax, including, without limitation, defects in the adoption of any underlying act of the Legislature authorizing such authorization, adoption, levy, assessment, collection, or enforcement, any failure to publish any notice which might otherwise be required with respect to any of the foregoing, or any failure by any such governing body to comply with any statutory requirement with respect to any of the foregoing matters; provided that this section shall not apply to any such tax, the validity of which is on the effective date hereof being challenged in any proceeding pending in any court in this state.