chore(deps): update pytest-cov requirement from <7,>=2 to >=2,<8 (#1741)

Author: dependabot[bot]

requirements/testing.txt

@@ -2,7 +2,7 @@
 aiohttp<4  # used for a WebSocket server mock
 pytest>=7.0.1,<9
 pytest-asyncio<2  # for async
-pytest-cov>=2,<7
+pytest-cov>=2,<8
 # while flake8 5.x have issues with Python 3.12, flake8 6.x requires Python >= 3.8.1,
 # so 5.x should be kept in order to stay compatible with Python 3.7/3.8
 flake8>=5.0.4,<8