Update pytest requirement from <8,>=7.0.1 to >=7.0.1,<9 (#1472)

requirements/testing.txt

@@ -1,6 +1,6 @@
 # pip install -r requirements/testing.txt
 aiohttp<4  # used for a WebSocket server mock
-pytest>=7.0.1,<8
+pytest>=7.0.1,<9
 pytest-asyncio<1  # for async
 pytest-cov>=2,<5
 # while flake8 5.x have issues with Python 3.12, flake8 6.x requires Python >= 3.8.1,