fix(deps): update dependency pytest-cov to v6 (#218)

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

pyproject.toml

@@ -36,7 +36,7 @@ dev = [
     "ruff>=0.7.0,<0.8.0",
     "pytest>=8.3,<9",
     "build>=0.10,<1.3",
-    "pytest-cov>=4.0,<5.1",
+    "pytest-cov>=6,<7",
     "pre-commit",
     "httmock",
 ]