SteamVR Beta v2.18.1 brings more Linux fixes and general improvements

Valve released SteamVR Beta v2.18.1 with numerous improvements and fixes, especially for Linux. It adds tethered Quest support over USB via Steam Link Beta, fixes async reprojection on AMD GPUs, GPU selection, and compatibility with systems without systemd.

• Default environment is now Aurora with content-aware color tinting
• Added tethered Quest support over USB via Steam Link Beta
• Fixed async reprojection on AMD GPUs and GPU selection
• Fixed compatibility with systems without systemd