Bump test-unit from 3.3.9 to 3.6.2

Bumps [test-unit](https://github.com/test-unit/test-unit) from 3.3.9 to 3.6.2.
- [Release notes](https://github.com/test-unit/test-unit/releases)
- [Commits](test-unit/test-unit@3.3.9...3.6.2)

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

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

Gemfile

@@ -2,6 +2,6 @@ source "https://rubygems.org"
 
 gem "rake"
 gem "rake-compiler"
-gem "test-unit", "~> 3.3.9"
+gem "test-unit", "~> 3.6.2"
 
 gemspec

Gemfile.lock

@@ -6,11 +6,11 @@ PATH
 GEM
   remote: https://rubygems.org/
   specs:
-    power_assert (2.0.1)
+    power_assert (2.0.3)
     rake (13.0.6)
     rake-compiler (1.1.1)
       rake
-    test-unit (3.3.9)
+    test-unit (3.6.2)
       power_assert
 
 PLATFORMS
@@ -19,7 +19,7 @@ PLATFORMS
 DEPENDENCIES
   rake
   rake-compiler
-  test-unit (~> 3.3.9)
+  test-unit (~> 3.6.2)
   version_sorter!
 
 BUNDLED WITH