[co2][tests] Fix co2 tests by increasing timeout for parallel tests

The tests fail on buildbot due to a timeout. Some ran through 58% others 84%

I doubled the timeout to 600s and hope this helps. I guess they are all run at the same time and our buildbot is simply to slow? Or can we manage it in a way that they are not run at the same time?

See e.g. https://git.iws.uni-stuttgart.de/buildbot/#/builders/10/builds/31