Fix stubtest for sqlalchemy.testing.plugin.pytestplugin (#9533)

stubs/SQLAlchemy/@tests/requirements-stubtest.txt

@@ -0,0 +1 @@
+pytest

stubs/SQLAlchemy/@tests/stubtest_allowlist.txt

@@ -59,10 +59,7 @@ sqlalchemy.testing.provision.stop_test_class_outside_fixtures
 sqlalchemy.testing.provision.temp_table_keyword_args
 sqlalchemy.testing.provision.update_db_opts
 
-# requires other packages
-sqlalchemy.testing.plugin.pytestplugin
-
-# can't be imported
+# KeyError/AttributeError on import due to dynamic initialization from a different module
 sqlalchemy.testing.fixtures
 sqlalchemy.testing.pickleable
 sqlalchemy.testing.plugin.bootstrap

stubs/SQLAlchemy/sqlalchemy/testing/plugin/pytestplugin.pyi

@@ -1,9 +1,8 @@
-from typing import Any
+from typing_extensions import Final
 
 from . import plugin_base
 
-has_xdist: bool
-py2k: Any
+py2k: Final = False
 
 def pytest_addoption(parser) -> None: ...
 def pytest_configure(config) -> None: ...
@@ -14,8 +13,6 @@ def collect_types_fixture() -> None: ...
 def pytest_sessionstart(session) -> None: ...
 def pytest_sessionfinish(session) -> None: ...
 def pytest_collection_finish(session): ...
-def pytest_configure_node(node) -> None: ...
-def pytest_testnodedown(node, error) -> None: ...
 def pytest_collection_modifyitems(session, config, items): ...
 def pytest_pycollect_makeitem(collector, name, obj): ...
 def pytest_runtest_setup(item) -> None: ...