Remove expensive tokenization for key uniqueness check

[phofl]

Closes #xxxx

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

This can be pretty expensive and the use of this check is more or less nonexistent. Comparing the dependencies itself is sufficient for what we want to do here.

[fjetter]

It's also known for many false positives in the xarray space. We hope that the root cause that led us to implement this check will be fixed medium term anyhow by our push for array expressions

[github-actions]

Unit Test Results

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

    27 files  ±  0      27 suites  ±0   11h 24m 18s ⏱️ + 1m 14s
 4 105 tests  -  15   3 987 ✅  -  19    111 💤 ±0  6 ❌ +3  1 🔥 +1 
51 473 runs   - 194  49 169 ✅  - 199  2 297 💤 +1  6 ❌ +3  1 🔥 +1 

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

Results for commit d4a8c36. ± Comparison against base commit 33b229a.

This pull request removes 15 tests.

distributed.tests.test_scheduler ‑ test_resubmit_different_task_same_key_after_previous_is_done[False-less]
distributed.tests.test_scheduler ‑ test_resubmit_different_task_same_key_after_previous_is_done[False-more]
distributed.tests.test_scheduler ‑ test_resubmit_different_task_same_key_after_previous_is_done[False-same]
distributed.tests.test_scheduler ‑ test_resubmit_different_task_same_key_after_previous_is_done[True-less]
distributed.tests.test_scheduler ‑ test_resubmit_different_task_same_key_after_previous_is_done[True-more]
distributed.tests.test_scheduler ‑ test_resubmit_different_task_same_key_after_previous_is_done[True-same]
distributed.tests.test_scheduler ‑ test_resubmit_different_task_same_key_before_previous_is_done[less]
distributed.tests.test_scheduler ‑ test_resubmit_different_task_same_key_before_previous_is_done[more]
distributed.tests.test_scheduler ‑ test_resubmit_different_task_same_key_before_previous_is_done[same]
distributed.tests.test_scheduler ‑ test_resubmit_different_task_same_key_many_clients
…

♻️ This comment has been updated with latest results.