chore: bump psutil from 5.9.3 to 5.9.4 in /tests

Bumps [psutil](https://github.com/giampaolo/psutil) from 5.9.3 to 5.9.4.
- [Release notes](https://github.com/giampaolo/psutil/releases)
- [Changelog](https://github.com/giampaolo/psutil/blob/master/HISTORY.rst)
- [Commits](https://github.com/giampaolo/psutil/compare/release-5.9.3...release-5.9.4)

---
updated-dependencies:
- dependency-name: psutil
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

tests/requirements_py3.txt

@@ -11,7 +11,7 @@ invoke==1.7.3
 packaging==21.3
 pathlib2==2.3.7.post1
 pluggy==1.0.0
-psutil==5.9.3
+psutil==5.9.4
 py==1.11.0
 pycparser==2.21
 PyNaCl==1.5.0