fix: panics in multi-threaded environments

Mause#1190 (comment)

Resolves Mause#1190

duckdb_engine/__init__.py

@@ -194,7 +194,7 @@ def __init__(self, dialect: "Dialect", **kwargs: Any) -> None:
         self.reserved_words.update(
             {
                 keyword_name
-                for (keyword_name,) in duckdb.execute(
+                for (keyword_name,) in duckdb.cursor().execute(
                     "select keyword_name from duckdb_keywords() where keyword_category == 'reserved'"
                 ).fetchall()
             }