GH-1078: Use JDK 23 instead of 25 in CI test matrix

JDK 25 is too early-access: no Docker images available and Spotless
plugin is incompatible. Switch to JDK 23 which has stable tooling.

Author: jbonofre

.github/workflows/test.yml

@@ -45,16 +45,14 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        jdk: [17, 21, 25]
+        jdk: [17, 21, 23]
         maven: [3.9.9]
         image: [ubuntu, conda-jni-cdata]
         include:
           - image: ubuntu
             name: "Ubuntu"
           - image: conda-jni-cdata
             name: "Conda JNI"
-    # JDK 25 is early-access; Docker images may not be available yet
-    continue-on-error: ${{ matrix.jdk == 25 }}
     env:
       JDK: ${{ matrix.jdk }}
       MAVEN: ${{ matrix.maven }}