Reuse parser name lookups when interning

[charliermarsh]

Use hashbrown's borrowed-entry insertion for long parser names so a missing name reuses its lookup when it is inserted. Construct the heap-backed Name only on a miss, while preserving the inline bypass and shared allocations for repeated long names.

[astral-sh-bot]

Typing conformance results

No changes detected ✅

Current numbers

The percentage of diagnostics emitted that were expected errors held steady at 97.84%. The percentage of expected errors that received a diagnostic held steady at 96.45%. The number of fully passing files held steady at 128/145.

[astral-sh-bot]

Memory usage report

Memory usage unchanged ✅

[astral-sh-bot]

ecosystem-analyzer results

No diagnostic changes detected ✅

Flaky changes detected. This PR summary excludes flaky changes; see the HTML report for details.

Full report with detailed diff (timing results)

[astral-sh-bot]

ruff-ecosystem results

Linter (stable)

✅ ecosystem check detected no linter changes.

Linter (preview)

✅ ecosystem check detected no linter changes.

Formatter (stable)

✅ ecosystem check detected no format changes.

Formatter (preview)

✅ ecosystem check detected no format changes.