[13.0] Fix missing rollback on retried jobs

[guewen]

Port from #284 / #311

When RetryableJobError was raised, any change done by the job was not
rollbacked.

Using raise would throw the exception up to the core and rollback, but
we would have a stack trace in the logs for each try. Calling rollback
manually (rollback also clears the env) hide the tracebacks, however,
when the last try fails, the full traceback is still shown in the logs.

Fixes #261

[guewen]

There is an issue because the job has a date_done date set at the retry

[guewen]

There is an issue because the job has a date_done date set at the retry

Fixed by the last commit, not a new thing.

[guewen]

However, the raise means we have a full stack trace every time, filling the logs. In the case of a retryable error, we don't want the exception stack everytime, only on the last one. I'll see if we can handle the rollback locally.

[guewen]

@wpichler @agenterp I modified code to manually rollback / clear the env instead of raising, to prevent cluttering the logs with stack traces. Can you check? (same on #311)

[guewen]

/ocabot merge patch

[OCA-git-bot]

What a great day to merge this nice PR. Let's do it!
Prepared branch 13.0-ocabot-merge-pr-312-by-guewen-bump-patch, awaiting test results.

[OCA-git-bot]

Congratulations, your PR was merged at f707889. Thanks a lot for contributing to OCA. ❤️