Merge pull request #647 from ruby/fix-windows-ci

The old Ruby version of Windows is broken

Author: hsbt

.github/workflows/test.yml

@@ -27,7 +27,8 @@ jobs:
             ruby: 2.4
           - os: macos-latest
             ruby: 2.5
-          - os: macos-latest
+          - os: windows-latest
+            ruby: 2.3
           - os: windows-latest
             ruby: truffleruby
           - os: windows-latest