Update pytest-cov requirement from ==3.* to ==4.* (#236)

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>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Maciej Dąbrowski <51504507+mdabrowski1990@users.noreply.github.com>

Author: dependabot[bot]

tests/requirements_for_software_tests.txt

@@ -1,4 +1,4 @@
 pytest==7.*
-pytest-cov==3.*
+pytest-cov==4.*
 pytest-asyncio>=0.17.2
 mock==5.*