[PR] Raise TypeError for async validators under the sync Driver [hamilton]

["digit50 (via GitHub)" <gi...@apache.org>]

digit50 opened a new pull request, #1764:
URL: https://github.com/apache/hamilton/pull/1764

   closes https://github.com/apache/hamilton/issues/1759
   
   An `AsyncDataValidator` used with the synchronous `Driver` failed with `AttributeError: 'coroutine' object has no attribute 'passes'` and a "coroutine was never awaited" warning, instead of the `TypeError` the data quality docs describe. The async validator gets an `async def` wrapper node, the sync driver stores its unawaited coroutine as the node result, and `final_node_callable` handed that coroutine to `act_warn` / `act_fail_bulk`.
   
   ## Changes
   
   - `hamilton/function_modifiers/validation.py`: in `final_node_callable`, if a validator node's result is a coroutine, close it and raise `TypeError` naming the validator and saying to use `AsyncDriver` (same message as the existing guard in the sync wrapper). The async wrapper and the `AsyncDriver` path are unchanged, since under `AsyncDriver` the result is already awaited before it reaches the final node.
   
   ## How I tested this
   
   - Added `test_sync_driver_with_async_validator_raises_type_error` in `tests/function_modifiers/test_validation.py`, parametrized over `importance="warn"` and `"fail"`. It builds a sync `Driver` over a node decorated with `@check_output_custom(AsyncSampleDataValidator(...))`, asserts `execute` raises `TypeError` mentioning `AsyncDriver`, and asserts no "never awaited" `RuntimeWarning` is emitted. Both cases failed with the `AttributeError` before the change and pass after it.
   - `pytest tests/function_modifiers tests/plugins/test_polars*.py`: everything that passed before still passes. The polars plugin tests that fail locally fail the same way without this change (polars 2.0 removed arguments they use, and `xlsxwriter` is not installed).
   - `ruff check` and `ruff format --check` on the changed files are clean.
   
   ## Notes
   
   If a node has several async validators, only the first coroutine is closed before the error is raised; the others can still produce a "never awaited" warning when collected. The error raised is the same either way.
   
   ## Checklist
   
   - [x] PR has an informative and human-readable title (this will be pulled into the release notes)
   - [x] Changes are limited to a single goal (no scope creep)
   - [x] Code passed the pre-commit check & code is left cleaner/nicer than when first encountered.
   - [x] Any _change_ in functionality is tested
   - [ ] New functions are documented (with a description, list of inputs, and expected output)
   - [ ] Placeholder code is flagged / future TODOs are captured in comments
   - [ ] Project documentation has been updated if adding/changing functionality.
   


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