OPT: Update dependency pytest-cov to v6 ⬆️

Author: renovate[bot]

poetry.lock

@@ -132,7 +132,7 @@ optional = true
 [tool.poetry.group.dev.dependencies]
 mypy = "1.15.0"
 pytest = "8.3.5"
-pytest-cov = "5.0.0"
+pytest-cov = "6.2.1"
 types-requests = "^2.28.11.8"
 ruff = "0.11.8"
 pytest-recording = "0.13.4"