devel/py-game_sdl2, devel/renpy: update to 6.99.5 and switch to -sdk

• Install runtimes necessary to build game distributions for non-FreeBSD [1]
• Use vendor bytecode to avoid an issue with saves and workaround build now failing without X11 connection

Changes: http://www.renpy.org/doc/html/changelog.html#ren-py-6-99-5
PR: 201322 [1]