Update pytest requirement from <7,>=6.2.5 to >=6.2.5,<9 (#1043)

Author: dependabot[bot]

requirements/testing_without_asyncio.txt

@@ -1,5 +1,5 @@
 # pip install -r requirements/testing_without_asyncio.txt
-pytest>=6.2.5,<7
+pytest>=6.2.5,<9
 pytest-cov>=3,<5
 black==22.8.0             # Until we drop Python 3.6 support, we have to stay with this version
 click<=8.0.4              # black is affected by https://github.com/pallets/click/issues/2225