Previously the workers were rolling back the database transaction in
this scenario which is wrong and causes an unnecessary alert if
aborted transactions are being monitored on the database server side.

fix(gc): commit database transaction when no task was found

See merge request !792

## [3.14.2](v3.14.1-gitlab...v3.14.2-gitlab) (2021-11-03)

### Bug Fixes

* **gc:** commit database transaction when no task was found ([2f4e2f94](2f4e2f94))