CI: fix simulator test

[gast04]

according to the messages

Restarting bridge. Retries left 0. Error: time-out of 5000ms while waiting for the simulator, make sure the simulator is ready and connected to 127.0.0.1:2000

the simulator CI issues are most likely timing issues, that carla doesnt steart fast enough, added a 4s sleep, and didnt fail for 3 times in a row