Merge pull request #352 from commonmark/java-23-ci

Test on Java 23 as well

Author: robinst

.github/workflows/ci.yml

@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        java: [11, 17, 21]
+        java: [11, 17, 21, 23]
     steps:
       - name: Checkout sources
         uses: actions/checkout@v4