chore(deps-dev): update pytest-cov requirement (#39)

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@v4.0.0...v5.0.0)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

pyproject.toml

@@ -49,7 +49,7 @@ homepage = "https://github.com/k4black/codebleu"
 [project.optional-dependencies]
 test = [
     "pytest >=7.0.0,<9.0.0",
-    "pytest-cov >=4.0.0,<5.0.0",
+    "pytest-cov >=4.0.0,<6.0.0",
     "pytest-mock >=3.0.0,<4.0.0",
     "pytest-timeout >=2.0.0,<3.0.0",
     "black ==24.3.0",