[Bug]: Potential Thread Safety Issue With DuckDBIdentifierPreparer

[greenmtnboy]

What happened?

When instantiating a bunch of memory engines in different threads, I can somewhat reliably get crashes/deadlocks on Windows when parallelism goes past 5 threads or so. It seems to be the global cursor object being used in the identifier preparer (in that if I remove that, everything is fine up to arbitrarily high thread counts (100+)).

I'm not sure if this is really a core use case, given that the Engines are probably created once typically, but wanted to flag just in case.

class DuckDBIdentifierPreparer(PGIdentifierPreparer):
    def __init__(self, dialect: "Dialect", **kwargs: Any) -> None:
        super().__init__(dialect, **kwargs)

        self.reserved_words.update(
            {
                keyword_name
                for (keyword_name,) in duckdb.cursor()
                .execute(
                    "select keyword_name from duckdb_keywords() where keyword_category == 'reserved'"
                )
                .fetchall()
            }
        )

Repo is just with a query to create an engine and do a select 1 and return.

def main():
    """
    Main function to initialize and run the threads.
    """
    num_threads = 100
    threads = []
    
    print(f"Starting execution with {num_threads} threads...")

    for i in range(1, num_threads + 1):
        # Create a Thread object, target is the function, args are the arguments for the function
        thread = threading.Thread(target=run_duckdb_query, args=(i,))
        threads.append(thread)
        thread.start()
        print(f"Main: Thread {i} started.")

    # Wait for all threads to complete
    for thread in threads:
        thread.join()

    print("\nAll threads have completed their execution.")

if __name__ == "__main__":
    main()```

### DuckDB Engine Version

duckdb-engine-0.17.0

### DuckDB Version

1.3.2

### SQLAlchemy Version

_No response_

### Relevant log output

```shell

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