chore(deps): update dependency pytest-cov to v6

Author: renovate[bot]

pyproject.toml

@@ -31,7 +31,7 @@ gh-pages = ["tinycss2"]
 [tool.poetry.group.dev.dependencies]
 mypy = "^1.8.0"
 pytest = "^8.0.0"
-pytest-cov = "^5.0.0"
+pytest-cov = "^6.0.0"
 ruff = "^0.6.0"
 types-pygments = "^2.17.0.20240106"
 types-colorama = "^0.4.15.20240205"