devel/renpy: update to 7.4.8

Changes: https://www.renpy.org/release/7.4.8 (see Announcment)
Changes: https://www.renpy.org/doc/html/changelog.html#renpy-7-4-8
Reported by: portscout, Repology

(cherry picked from commit 5262cba6b8da8d89bd26e3a8bfeeaa6641995ef8)