scripts: Initialize renderdoc environment

In some cases this seems to be required to avoid issues with X11
display connections.

Signed-off-by: Alexandros Frantzis <alexandros.frantzis@collabora.com>
4 jobs for failing-benchmark in 16 minutes and 25 seconds (queued for 1 minute and 12 seconds)
latest
Status Job ID Name Coverage
  Containers Build
passed #664740
debian

00:00:21

 
  Build
passed #664741
mesa-build

00:05:52

 
  Test
passed #664743
intel
conformance-intel

00:10:12

passed #664742
conformance-softpipe

00:05:25