Remove EOL Ruby versions from matrix example in README

Author: fkmy

README.md

@@ -98,7 +98,7 @@ jobs:
       matrix:
         os: [ubuntu-latest, macos-latest]
         # Due to https://github.com/actions/runner/issues/849, we have to use quotes for '3.0'
-        ruby: ['2.7', '3.0', '3.1', '3.2', '3.3', '3.4', '4.0', head, jruby, jruby-head, truffleruby, truffleruby-head]
+        ruby: ['3.3', '3.4', '4.0', head, jruby, jruby-head, truffleruby, truffleruby-head]
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v6