textproc/py-openpyxl: Upgrade port to 3.1.5

• Update COMMENT directly from WWW

Approved by: antoine (maintainer)
Differential Revision: https://reviews.freebsd.org/D53690
Release Notes: https://foss.heptapod.net/openpyxl/openpyxl/-/blob/13627b03ca25a1a98becf40e533b955615b13429/doc/changes.rst?plain=1#L1