fix: drop ruby 2.6 from CI

Author: Justintime50

.github/workflows/ci.yml

@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        rubyversion: ['2.6', '2.7', '3.0', '3.1', '3.2', '3.3', '3.4']
+        rubyversion: ['2.7', '3.0', '3.1', '3.2', '3.3', '3.4']
     steps:
       - uses: actions/checkout@v4
       - uses: ruby/setup-ruby@v1