Updated build matrix for JDKs

Signed-off-by: Patrick Reinhart <patrick@reini.net>

Author: reinhapa

.github/workflows/gradle.yml

@@ -1,6 +1,3 @@
-# This workflow will build a Java project with Gradle
-# For more information see: https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-gradle
-
 name: CI
 
 on:
@@ -22,7 +19,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        jdk: ['11', '22']
+        jdk: ['11', '21','23']
         os: [ubuntu-latest]
     steps:
     - uses: actions/checkout@v4