message: test: add test for when fsspec isn't installed
diff: import logging
  +import sys
  from pathlib import Path
  from shutil import copyfileobj
  from typing import Callable
  from duckdb import DuckDBPyConnection, InvalidInputException
  -from pytest import raises, importorskip, fixture
  +from pytest import raises, importorskip, fixture, MonkeyPatch
  importorskip('fsspec', '2022.11.0')
  from fsspec import filesystem, AbstractFileSystem
  @@ -97,3 +98,9 @@ class TestPythonFilesystem:
  duckdb_cursor.execute(f'''COPY (SELECT 1) TO 'memory://{filename}' (FORMAT PARQUET);''')
  assert memory.open(filename).read().startswith(b'PAR1')
  +
  + def test_when_fsspec_not_installed(self, duckdb_cursor: DuckDBPyConnection, monkeypatch: MonkeyPatch):
  + monkeypatch.setitem(sys.modules, 'fsspec', None)
  +
  + with raises(ModuleNotFoundError):
  + duckdb_cursor.register_filesystem(None)
  