segfault when using EXPLAIN in Python API

[lehners]

A segmentation fault is thrown when i execute EXPLAIN commands with the Python API 0.0.4.

Minimal example to reproduce the behavior:

import kuzu
import os
import shutil

db_file = './testdb'
if os.path.exists(db_file):
    shutil.rmtree(db_file)

# create database
db = kuzu.Database(db_file)
# create connection
conn = kuzu.Connection(db)

# create schema
conn.execute("CREATE NODE TABLE User(name STRING, age INT64, PRIMARY KEY (name))")
# load data


# issue a query
results = conn.execute('EXPLAIN MATCH (u:User) RETURN u.name;')
# iterate result
while results.has_next():
    print(results.get_next())