[omdb] add --no-executing-info to the other background-tasks commands (#8906)

In `test_omdb_success_cases`, we previously
(#8840) added
`--no-executing-info` to one of the commands. I somehow completely
missed that there were a number of other `background-tasks` commands all
of which are flaky in the same way -- add this flag to all of them.

Author: sunshowers