containers: Fix github test "webui-docker-compose" timeout
The test webui-docker-compose exceeds 30 minutes and is cancelled with the message
"The job running on runner Hosted Agent has exceeded the maximum execution time of 30 minutes."
- AC 1: The test is executed without being cancelled
Example of crenellation: https://github.com/os-autoinst/openQA/actions/runs/725105078
The PR itself is ok to fix the exceptional cases when downloading packages for docker-compose takes that long that 30m is exceeded but concerns had been raised in https://github.com/os-autoinst/openQA/pull/3827#issuecomment-814865637 and https://github.com/os-autoinst/openQA/pull/3827#issuecomment-814968080 and https://github.com/os-autoinst/openQA/pull/3827#pullrequestreview-630154659 that 30m is too long as a common runtime for PR checks which can be adressed in this ticket or a follow-up. After merge I suggest you create a follow-up ticket which we put to "future" for now until we see that the "test runs too long" bothers us enough that we care to fix it :)