Merge pull request #244 from ruby-syntax-tree/dependabot/bundler/test-unit-3.6.9

Bump test-unit from 3.6.8 to 3.6.9

Author: github-actions[bot]

Gemfile.lock

@@ -10,7 +10,7 @@ GEM
     rouge (4.5.2)
     syntax_tree (6.2.0)
       prettier_print (>= 1.2.0)
-    test-unit (3.6.8)
+    test-unit (3.6.9)
       power_assert
 
 PLATFORMS