Merge pull request #212 from ruby-syntax-tree/dependabot/bundler/test-unit-3.5.9

Bump test-unit from 3.5.8 to 3.5.9

Author: github-actions[bot]

Gemfile.lock

@@ -10,7 +10,7 @@ GEM
     rouge (4.1.1)
     syntax_tree (6.1.1)
       prettier_print (>= 1.2.0)
-    test-unit (3.5.8)
+    test-unit (3.5.9)
       power_assert
 
 PLATFORMS