Update pytest-cov requirement from ^3.0.0 to >=3,<5

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@v3.0.0...v4.1.0)

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

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

pyproject.toml

@@ -31,7 +31,7 @@ asteval = "^0.9.27"
 DFO-LS = {version = "^1.2", optional = true}
 xarray = ">=0.16,<2023.2"
 pytest = {version = "^7.0.0", optional = true}
-pytest-cov = {version = "^3.0.0", optional = true}
+pytest-cov = {version = ">=3,<5", optional = true}
 codecov = {version = "^2.1.11", optional = true}
 flake8 = {version = "^5.0", optional = true}
 tox-gh-actions = {version = "^2.11", optional = true}