wip 2.6

Author: toshimaru

.github/workflows/test.yml

@@ -6,7 +6,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest]
-        ruby: ["2.7", "3.0", "3.1", "3.2", "3.3", "3.4"]
+        ruby: ["2.6", "2.7", "3.0", "3.1", "3.2", "3.3", "3.4"]
     runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4