Dask order uses task_spec

[fjetter]

This builds on #8797

The relevant commit is 919ff4f

This removes the need to materialize and copy the dependencies to a dict.

Needs dask/dask#11347

[github-actions]

Unit Test Results

See test report for an extended history of previous test failures. This is useful for diagnosing flaky tests.

    18 files   -      7      18 suites   - 7   6h 55m 23s ⏱️ - 3h 14m 4s
 4 114 tests  -      8   3 856 ✅  -    150    114 💤 +  3  143 ❌ +138  1 🔥 +1 
34 449 runs   - 13 166  32 406 ✅  - 13 095  1 602 💤  - 506  439 ❌ +433  2 🔥 +2 

For more details on these failures and errors, see this check.

Results for commit 0ef6e89. ± Comparison against base commit 2e61816.

This pull request removes 10 and adds 2 tests. Note that renamed tests count towards both.

distributed.tests.test_client ‑ test_persist_get
distributed.tests.test_client ‑ test_recreate_error_array
distributed.tests.test_client ‑ test_recreate_error_collection
distributed.tests.test_client ‑ test_recreate_error_delayed
distributed.tests.test_client ‑ test_recreate_error_futures
distributed.tests.test_client ‑ test_recreate_task_array
distributed.tests.test_client ‑ test_recreate_task_collection
distributed.tests.test_client ‑ test_recreate_task_delayed
distributed.tests.test_client ‑ test_recreate_task_futures
distributed.tests.test_utils ‑ test_maybe_complex

distributed.tests.test_client ‑ test_persist_get[False]
distributed.tests.test_client ‑ test_persist_get[True]

This pull request skips 3 tests.

distributed.shuffle.tests.test_merge ‑ test_minimal_version
distributed.tests.test_client ‑ test_computation_object_code_not_available
distributed.tests.test_worker_client ‑ test_submit_different_names

♻️ This comment has been updated with latest results.