Use function-scoped catalog fixture for the test suite

This increases test suite run times substantially, but test independence is more important.

Switching from module- to function-scoped exposed an additional test failure relating to marksparkza#65, for example, where the module-scoped catalog had allowed a schema cached in one test to be loaded in the next test, thereby masking an internal error.

Author: marksparkza

tests/test_suite.py

@@ -3,15 +3,21 @@
 
 import pytest
 
-from jschon import Catalog, JSON, JSONSchema, LocalSource, URI
+from jschon import JSON, JSONSchema, LocalSource, URI, create_catalog
 from jschon.utils import json_loadf
 from tests import metaschema_uri_2019_09, metaschema_uri_2020_12, metaschema_uri_next
 
 testsuite_dir = pathlib.Path(__file__).parent / 'JSON-Schema-Test-Suite'
 
 
-@pytest.fixture(scope='module', autouse=True)
-def configure_catalog(catalog: Catalog):
+@pytest.fixture(autouse=True)
+def catalog():
+    # replaces the catalog fixture in conftest, for this test module
+    catalog = create_catalog(
+        '2019-09',
+        '2020-12',
+        'next',
+    )
     catalog.add_uri_source(
         URI('http://localhost:1234/'),
         LocalSource(testsuite_dir / 'remotes'),