[unsupervised AI] Preserve worker name restrictions across restarts

[Excelius-Wang]

Note

I have reviewed, understood, and approved the implementation and tests in this pull request.

Closes #8600

Worker restrictions submitted by name are currently normalized to the
worker's concrete address. When a nanny restarts that worker, its address
changes while existing tasks retain the stale address and become
unschedulable.

This change preserves recognized worker names in TaskState and resolves
them through the scheduler's existing alias map when selecting workers.
The P2P shuffle scheduler plugin uses the same resolver where it requires
concrete worker addresses.

• Tests added / passed
• Passes pixi run lint
  • Pixi was unavailable locally. The changed-file Ruff, formatting, and
    Mypy hooks passed.

Tests:

• pytest --runslow -q distributed/tests/test_client.py -k 'restriction or restart_workers'
• pytest --runslow -q distributed/tests/test_scheduler.py -k 'valid_worker or restriction or alias'
• pytest --runslow -q distributed/shuffle/tests/test_shuffle.py::test_crashed_other_worker_during_barrier

[github-actions]

Unit Test Results

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

    40 files  ± 0      40 suites  ±0   14h 32m 53s ⏱️ +52s
 4 161 tests + 1   3 981 ✅ + 1    178 💤 ±0  2 ❌ ±0 
80 979 runs  +18  76 739 ✅ +22  4 238 💤  - 4  2 ❌ ±0 

For more details on these failures, see this check.

Results for commit 5f36046. ± Comparison against base commit dc182bd.