Bump coverage from 6.4.3 to 6.5.0 in /requirements (#517)

Bumps [coverage](https://github.com/nedbat/coveragepy) from 6.4.3 to 6.5.0.
- [Release notes](https://github.com/nedbat/coveragepy/releases)
- [Changelog](https://github.com/nedbat/coveragepy/blob/master/CHANGES.rst)
- [Commits](nedbat/coveragepy@6.4.3...6.5.0)

---
updated-dependencies:
- dependency-name: coverage
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

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

Author: dependabot[bot]

requirements/requirements_test.txt

@@ -3,4 +3,4 @@ pytest-cov==4.0.0
 pytest-rerunfailures==10.2
 pyvista==0.36.1
 ansys-platform-instancemanagement==1.0.2
-coverage==6.4.3
+coverage==6.5.0