fix(api): stop swallowing document indexing errors in create handler

[Harsh23Kashyap]

Fixes #38190

Summary

The create_document_index event handler wrapped IndexingRunner.run in contextlib.suppress(Exception), which swallowed every indexing failure and made the inner DocumentIsPausedError handler useless for unexpected errors.

This change removes the suppress wrapper and matches the logging pattern used in document_indexing_task: log pauses at info level and log unexpected failures with logger.exception.

Test plan

• cd api && uv run --group dev python -m pytest tests/unit_tests/events/event_handlers/test_create_document_index.py -q (3 passed)
• uv run --group dev ruff check events/event_handlers/create_document_index.py tests/unit_tests/events/event_handlers/test_create_document_index.py

[github-actions]

Pyrefly Type Coverage

Metric	Base	PR	Delta
Type coverage	51.86%	51.86%	0.00%
Strict coverage	51.38%	51.38%	0.00%
Typed symbols	31,539	31,539	0
Untyped symbols	29,545	29,545	0
Modules	2952	2952	0

[Harsh23Kashyap]

Hey, this PR is ready for review when you have a chance. Happy to adjust if anything needs changing.

[Harsh23Kashyap]

Synced with latest main (behind 0). fatelei asked about logging level on the handler — switched unexpected failures to logger.warning (ruff TRY400 blocks bare logger.error in except without exc_info). Regression tests updated; thread resolved.

Verification: cd api && uv run --group dev python -m pytest tests/unit_tests/events/event_handlers/test_create_document_index.py -q → 3 passed.

CI is mostly green; a few jobs were still finishing on the last run. Happy to adjust if you want logger.error(..., exc_info=True) instead.