Fixed ResourceWarnings in tests (#1366)

* #1320 Update pytest configuration and tests cleanup

This commit modifies the pytest's configuration file, `pyproject.toml`, to remove filterwarnings settings. It also makes changes in various test files; the Redis isolation test is now using the provided `redis_storage` fixture instead of setting up its own connection, pytest.mark.filterwarnings is no longer used in `test_isolation.py` and `test_aiohttp_session.py` properly closes off sessions.

* Added changelog

* Fixed coverage for the RedisEventIsolation

tests/test_api/test_client/test_session/test_aiohttp_session.py

@@ -96,6 +96,8 @@ class TestAiohttpSession:
             await session.close()
             mocked_close.assert_called_once()
 
+        await session.close()
+
     def test_build_form_data_with_data_only(self, bot: MockedBot):
         class TestMethod(TelegramMethod[bool]):
             __api_method__ = "test"