Exclude older than 2.6 on macos-14

Author: nobu

.github/workflows/test.yml

@@ -15,6 +15,8 @@ jobs:
         ruby: ${{ fromJson(needs.ruby-versions.outputs.versions) }}
         os: [ ubuntu-latest, macos-latest, windows-latest ]
         exclude:
+          - { os: macos-latest, ruby: 2.4 }
+          - { os: macos-latest, ruby: 2.5 }
           - { os: windows-latest, ruby: truffleruby-head }
           - { os: windows-latest, ruby: truffleruby }
     runs-on: ${{ matrix.os }}