Import/Export workers are not prepared to be retried. Until this is
solved they should not go to the dead queue as well.

Related to:
- https://gitlab.com/gitlab-org/gitlab/-/issues/16812
- https://gitlab.com/gitlab-org/gitlab/-/issues/238572
- https://gitlab.com/gitlab-org/gitlab/-/issues/227419
- https://gitlab.com/gitlab-org/gitlab/-/merge_requests/35344