fix: set namespace commit handler for LanceDataset.commit

[jackye1995]

Also added helper function extract_namespace_arc for shared logic

[github-actions]

Code Review

P1: Missing validation for namespace/table_id pair

The commit method changes add namespace and table_id parameters, but there's no validation that both must be provided together. If a user provides only one parameter, managed versioning is silently skipped.

In python/python/lance/dataset.py around line 3535-3561: Add validation before passing to Rust:

if (namespace is None) != (table_id is None):
    raise ValueError("Both 'namespace' and 'table_id' must be provided together.")

This follows the existing pattern in the codebase (see __init__.py:204, __init__.py:231, dataset.py:5758, dataset.py:5844).

Minor note

The namespace extraction logic in dataset.rs:2260-2293 duplicates existing code from the Dataset::new method (lines 611-648). Consider extracting this into a helper function to avoid divergence, though this is not blocking.

[jackye1995]

depreacted clippy lint