Bumped pytest

[gandiddi]

Fixes #2168

Description

[botbuilder.testing] Relax dependency to allow pytest 8

Specific Changes

• Updated pytest version to 8.3.3
• Updated pytest-asyncio version to 0.24.0
• Updated pytest-cov version to >=5.0.0
• Fixed ModuleNotFoundError: No module named 'simple_adapter' in test_teams_activity_handler.py
• Fixed PytestAssertRewriteWarning: assertion is always true, perhaps remove parentheses? in test_choice_recognizers.py

Testing

Ran the pip install commands and pytest in the following Python versions, and they are working as expected
Python 3.13.0, 3.12.5, 3.11.9, 3.10.11, 3.9.13, 3.8.10