[bug#69971] Explanation

[Abhishek Cherath <abhi@quic.us>]

Hello,

So this patch fixes two things. First, it gives the webkit gtk process
access to va-api drivers, which allows hardware acceleration for video
and prevents the errors below:

0:00:00.489161195    21       0xfd4200 INFO               vadisplay gstvadisplay.c:268:_va_info:<vadisplaydrm2> VA info: Trying to open /home/abhishek/.guix-profile/lib/dri/i965_drv_video.so
0:00:00.489224548    21       0xfd4200 INFO               vadisplay gstvadisplay.c:268:_va_info:<vadisplaydrm2> VA info: Trying to open /run/current-system/profile/lib/dri/i965_drv_video.so
0:00:00.489278879    21       0xfd4200 INFO               vadisplay gstvadisplay.c:268:_va_info:<vadisplaydrm2> VA info: va_openDriver() returns -1
0:00:00.489287135    21       0xfd4200 WARN               vadisplay gstvadisplay.c:316:gst_va_display_initialize:<vadisplaydrm2> vaInitialize: unknown libva error
0:00:00.489302829    21       0xfd4200 ERROR            msdkcontext gstmsdkcontext.c:183:gst_msdk_context_use_vaapi: Couldn't create a VA DRM display

Second, it gives access to the locale dir, which silences some warnings
of the sort below:

(process:2): Gtk-WARNING **: 02:21:08.731: Locale not supported by C library.
	Using the fallback 'C' locale.

Yours sincerely,
Abhishek Cherath.