Add ubuntu-26.04 builds of CRuby 1.9.3 to 3.1.7

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: 2 people

.github/workflows/build.yml

@@ -10,8 +10,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ ubuntu-22.04, ubuntu-24.04, ubuntu-26.04, ubuntu-22.04-arm, ubuntu-24.04-arm, ubuntu-26.04-arm, macos-15-intel, macos-15 ]
-        ruby: [ruby-3.3.13, ruby-3.4.12, ruby-4.0.9]
+        os: [ ubuntu-26.04, ubuntu-26.04-arm ]
+        ruby: [ ruby-1.9.3-p551, ruby-2.0.0-p648, ruby-2.1.9, ruby-2.2.10, ruby-2.3.8, ruby-2.4.10, ruby-2.5.9, ruby-2.6.10, ruby-2.7.8, ruby-3.0.7, ruby-3.1.7 ]
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v6