src.conf(5): Remove the WITHOUT_GAMES build option

[gbe]

Summary

The BSD games moved to ports a while ago,
so the build option is long deprecated.

MFC after: 1 week

Test Plan

regenerate src.conf

[emaste]

there are still a few things controlled by WITH_/WITHOUT_GAMES:

$ git grep MK_GAMES
Makefile.inc1:.if ${MK_GAMES} != "no"
release/Makefile:           MK_GAMES=no \
tools/build/mk/OptionalObsoleteFiles.inc:.if ${MK_GAMES} == no
usr.bin/Makefile:SUBDIR.${MK_GAMES}+=   caesar
usr.bin/Makefile:SUBDIR.${MK_GAMES}+=   factor
usr.bin/Makefile:SUBDIR.${MK_GAMES}+=   fortune
usr.bin/Makefile:SUBDIR.${MK_GAMES}+=   grdc
usr.bin/Makefile:SUBDIR.${MK_GAMES}+=   morse
usr.bin/Makefile:SUBDIR.${MK_GAMES}+=   number
usr.bin/Makefile:SUBDIR.${MK_GAMES}+=   pom
usr.bin/Makefile:SUBDIR.${MK_GAMES}+=   primes
usr.bin/Makefile:SUBDIR.${MK_GAMES}+=   random

[pauamma_gundo.com]

share/man/man5/src.conf.5

1654

Should still be .Va, I think. (May instead need to be fixed in whatever creates src.conf.5 instead, if it's autogenerated as Phab says it is.)

[gbe]

fortune is still in base so the removal of the build knob is not an option.