connection closes after insert_all

[Florents-Tselai]

see a2ad654135a6d829dea40d01e3a12eae9fbee6c5

[Florents-Tselai]

Connections are closed implicitly when they go out of scope or if they are explicitly closed using close(). Once the last connection to a database instance is closed, the database instance is closed as well. See https://duckdb.org/docs/api/python/dbapi#default-connection