Update dependency pytest to v9 (#737)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

poetry.lock

@@ -57,7 +57,7 @@ mypy-extensions = "^1.0.0"
 pre-commit = "^3.6.0"
 pydocstyle = "^6.3.0"
 pylint = "^4.0.0"
-pytest = "^8.0.1"
+pytest = "^9.0.0"
 pyupgrade = "^3.4.0"
 safety = "^3.0.1"
 coverage = "^7.3.4"