Update pytest-cov requirement from <6 to <7

Updates the requirements on [pytest-cov](https://github.com/pytest-dev/pytest-cov) to permit the latest version.
- [Changelog](https://github.com/pytest-dev/pytest-cov/blob/master/CHANGELOG.rst)
- [Commits](pytest-dev/pytest-cov@v1.0...v6.0.0)

---
updated-dependencies:
- dependency-name: pytest-cov
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

pyproject.toml

@@ -36,7 +36,7 @@ dev = [
     "ruff",
     "pytest<9",
     "pytest-cache<2",
-    "pytest-cov<6",
+    "pytest-cov<7",
     "WebTest<4",
     "marshmallow<4",
     "colander<3",