Add a test for GraphLayout with scatter

[j-bennet]

Replace a test for TypeError for GraphLayout with scatter - this one triggers the same error that the customer experienced.

Follow-up for #8017 (comment).

Closes #xxxx

• Tests added / passed
• Passes pre-commit run --all-files

[github-actions]

Unit Test Results

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

       20 files  +       18         20 suites  +18   11h 15m 4s ⏱️ + 10h 47m 13s
  3 735 tests +  1 741    3 624 ✔️ +  1 815     106 💤  -      79  5 ❌ +5 
36 130 runs  +32 311  34 377 ✔️ +30 943  1 748 💤 +1 363  5 ❌ +5 

For more details on these failures, see this check.

Results for commit 45ac3dc. ± Comparison against base commit 70c9eb8.

This pull request removes 1 and adds 1742 tests. Note that renamed tests count towards both.

distributed.diagnostics.tests.test_graph_layout ‑ test_layout_with_priorities

distributed.cli.tests.test_dask_scheduler ‑ test_dashboard
distributed.cli.tests.test_dask_scheduler ‑ test_dashboard_allowlist
distributed.cli.tests.test_dask_scheduler ‑ test_dashboard_non_standard_ports
distributed.cli.tests.test_dask_scheduler ‑ test_dashboard_port_zero
distributed.cli.tests.test_dask_scheduler ‑ test_defaults
distributed.cli.tests.test_dask_scheduler ‑ test_hostport
distributed.cli.tests.test_dask_scheduler ‑ test_idle_timeout
distributed.cli.tests.test_dask_scheduler ‑ test_interface
distributed.cli.tests.test_dask_scheduler ‑ test_multiple_protocols
distributed.cli.tests.test_dask_scheduler ‑ test_multiple_workers
…

[hendrikmakait]

Has this test been removed intentionally? (I'm just wondering because the description says this adds a test, not that it replaces one.)

[j-bennet]

That's intentional. In the initial PR, I added a test with priorities, but I don't think it actually triggered the error case.

[hendrikmakait]

Thanks, @j-bennet!