Add 'INTERSECT' to Close Keywords in Where clause

[swarnat]

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Before submitting your pull request please have a look at the
following checklist:

• ran the tests (pytest)
• all style issues addressed (flake8)
• your changes are covered by tests
• your changes are documented, if needed

"INTERSECT" must be a closing keyword for WhereConverter. Otherwise SQL Queries, which use that combination, cannot be parsed.
Docs: https://learn.microsoft.com/en-us/sql/t-sql/language-elements/set-operators-except-and-intersect-transact-sql?view=sql-server-ver17

[Copilot]

Pull request overview

This PR adds 'INTERSECT' as a closing keyword for the WHERE clause in the SQL parser, ensuring that SQL queries using WHERE clauses followed by INTERSECT operations can be properly parsed.

• Added 'INTERSECT' to the M_CLOSE tuple of the Where class to handle INTERSECT set operations
• Aligns INTERSECT behavior with other set operators (UNION, UNION ALL, EXCEPT) that already close WHERE clauses
• Enables proper parsing of SQL queries containing WHERE...INTERSECT patterns

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[andialbrecht]

Thanks!