fix: tighten DuckDB WASM SQL patch wrapper

Author: peter-gy

marimo/_runtime/_wasm/_duckdb/__init__.py

@@ -433,17 +433,20 @@ def _wrapper(*args: Any, **kwargs: Any) -> Any:
             if frame is None or frame.f_back is None:
                 return original(*args, **kwargs)
             caller_frame = frame.f_back
+            eval_globals = caller_frame.f_globals
+            eval_locals = caller_frame.f_locals
             try:
                 return run_duckdb_sql_with_wasm_patch(
                     original,
                     args,
                     kwargs,
                     query_arg_index=query_arg_index,
                     query_kwarg_names=query_kwarg_names,
-                    eval_globals=caller_frame.f_globals,
-                    eval_locals=caller_frame.f_locals,
+                    eval_globals=eval_globals,
+                    eval_locals=eval_locals,
                 )
             finally:
+                del caller_frame
                 del frame
 
         return _wrapper
@@ -688,14 +691,19 @@ def _require_sqlglot() -> None:
 
 def _parse_duckdb_query(query: str) -> list[exp.Expression] | None:
     import sqlglot
+    from sqlglot import exp as sqlglot_exp
 
     try:
         parsed = sqlglot.parse(query, read="duckdb")
     except Exception as e:
         LOGGER.debug("Failed to parse DuckDB query for WASM patch: %s", e)
         return None
 
-    return [statement for statement in parsed if statement is not None]
+    return [
+        statement
+        for statement in parsed
+        if isinstance(statement, sqlglot_exp.Expression)
+    ]
 
 
 def _replace_remote_sources(