reset java to 25 in action yml

Author: bgruenba

.github/workflows/tdd-by-example-tests.yml

@@ -17,7 +17,7 @@ jobs:
     - name: Set up JDK 25
       uses: actions/setup-java@v4
       with:
-        java-version: '25'
+        java-version: '24'
         distribution: 'temurin'
         cache: maven
     - name: Test Java Chapter 1