Add Ruby 3.2 to the CI matrix

Author: petergoldstein

.github/workflows/test.yml

@@ -7,7 +7,7 @@ jobs:
     name: build (${{ matrix.ruby }} / ${{ matrix.os }})
     strategy:
       matrix:
-        ruby: [ 2.7, '3.0', 3.1, head ]
+        ruby: [ 2.7, '3.0', 3.1, 3.2, head ]
         os: [ ubuntu-latest, macos-latest, windows-latest ]
         exclude:
         - { os: windows-latest , ruby: head }