multimedia/py-mat2: update to 0.13.3

Changelog: https://0xacab.org/jvoisin/mat2/-/releases/0.13.3

MFH: 2023Q1
Approved by: flo (mentor)
Differential Revision: https://reviews.freebsd.org/D38773

(cherry picked from commit 11f5d028c4d9a1870ba7d35c9f8883d39fca6198)