emulators/mupen64plus-qt: Update to 1.17 and switch to Qt6

Take maintainership. The port has not been updated for a long time,
no response from maintainer almost for a year.

PR: 289727, 296783
Appproved by: maintainer timeout

(cherry picked from commit 7cf2899616d7279ff7ca947ff8eabf7b3016a17b)