play_yarg() hard-coded to windows

[Pantotone]

i believe it's the last thing to complete compatibility with other oses for now

Executable paths on another systems for YARG:

• Windows: {versionFolder}/YARG.exe (already implemented)
• MacOS/Darwin: {versionFolder}/YARG.app/Contents/MacOS/YARG
• Linux: {versionFolder}/YARG