Improve boefje runner error messages on container failure

Changes

The code logged an exception with stacktrace when the container returned a non-zero exit status, but this is confusing because nothing actually goes wrong inside the boefje runner when docker returns an error. To make it more confusing the message of exception that is logged might also contain a stack trace when the output of the docker container was a stacktrace. This change will just log an error message if docker returns an error instead of an exception with the strack trace.

Reraising the exception is not necessary anymore because this was already fixed by #3506 last week.

QA notes

For testing you can force the container to return nonzero by changing the boefje code, for example change the run function of kat_dnssec/main.py to:

def run(boefje_meta: dict):
    import sys
    sys.exit(1)

Then run "make build" to build a new dnssec container image. Running dnssec should then result in only a single error message in the boefje runner. The task should also have failed status.

Checklist for code reviewers:

Copy-paste the checklist from the docs/source/templates folder into your comment.

Checklist for QA:

Copy-paste the checklist from the docs/source/templates folder into your comment.

Checklist for QA:

[x] I have checked out this branch, and successfully ran a fresh make reset.
[x] I confirmed that there are no unintended functional regressions in this branch:
- [x] I have managed to pass the onboarding flow
- [x] Objects and Findings are created properly
- [x] Tasks are created and completed properly
[x] I confirmed that the PR's advertised feature or hotfix works as intended.
[x] I checked the logs for errors and/or warnings and made issues where necessary

What works:

The normalizer and boefje both fail after editing the file as mentioned in the QA notes. Seems to work as expected and doesn't seem to break anything obvious.

What doesn't work:

n/a

Bug or feature?:

n/a

minvws / nl-kat-coordination