Add: TuxRun and TuxLAVA repository

Add extrepo entry for TuxRun and TuxLAVA repository.

TuxRun and TuxLAVA are part of TuxSuite, a suite of tools and services to help with Linux kernel development.

Reference:

• https://tuxlava.org/
• https://tuxrun.org/

Signed-off-by: Kurva Prashanth krvprashanth@riseup.net