docker-compose.yaml: add lava-pengutronix runtime

Add runtime argument 'lava-pengutronix' to 'scheduler-lava' service.
This will enable the pipeline to run and submit jobs to Pengutronix LAVA
lab. This configuration file is still used by the staging environment.

Signed-off-by: Paweł Wieczorek <pawiecz@collabora.com>

docker-compose.yaml

@@ -91,6 +91,7 @@ services:
  - 'lava-baylibre'
  - 'lava-qualcomm'
  - 'lava-cip'
+ - 'lava-pengutronix'
  extra_hosts:
  - "host.docker.internal:host-gateway"