Bump test-unit from 3.5.7 to 3.6.1 (#335)

Bumps [test-unit](https://github.com/test-unit/test-unit) from 3.5.7 to 3.6.1.
- [Release notes](https://github.com/test-unit/test-unit/releases)
- [Commits](test-unit/test-unit@3.5.7...3.6.1)

---
updated-dependencies:
- dependency-name: test-unit
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

Gemfile.lock

@@ -187,7 +187,7 @@ GEM
       attr_required (>= 0.0.5)
       faraday (~> 2.0)
       faraday-follow_redirects
-    test-unit (3.5.7)
+    test-unit (3.6.1)
       power_assert
     timeout (0.3.0)
     tzinfo (2.0.6)