Bump ruby/setup-ruby from 1.207.0 to 1.215.0 (#129)

Author: dependabot[bot]

.github/workflows/rubocop.yml

@@ -16,7 +16,7 @@ jobs:
         uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332
 
       - name: Set up Ruby
-        uses: ruby/setup-ruby@4a9ddd6f338a97768b8006bf671dfbad383215f4
+        uses: ruby/setup-ruby@2654679fe7f7c29875c669398a8ec0791b8a64a1
         with:
           ruby-version: .ruby-version