New tests for gather_dep are flaky #5406
Description
The two tests introduced by #5160 are flaky:
FAILED distributed/tests/test_worker.py::test_gather_dep_do_not_handle_response_of_not_requested_tasks
FAILED distributed/tests/test_worker.py::test_gather_dep_no_longer_in_flight_tasks
They frequently fail with error message
E TypeError: tuple indices must be integers or slices, not str
See e.g.
- https://github.com/dask/distributed/actions/runs/1328839847
- https://github.com/dask/distributed/runs/3838904626
CC @fjetter