Update nvidia-beta-driver to 455.38
Changes:
- Added support for the GeForce RTX 3070
- Fixed a bug in nvidia-settings that caused the SLI Mosaic Configuration dialog to position available displays incorrectly when enabling SLI Mosaic
- Added support for using an NVIDIA-driven display as a PRIME Display Offload sink with a PRIME Display Offload source driven by the xf86-video-intel driver
- Fixed a bug in a Vulkan barrier optimization that allowed some back-to-back copies to run unordered
- Fixed a performance regression in the NVIDIA X driver which affected some X11 RENDER extension use cases
- Added AMD Secure Memory Encryption compatibility