Issue #139 Fix CI workflow for Java 24+ JTD codegen module

- Updated CI workflow to use Java 24 (required for JTD codegen module)
- Changed distribution from temurin to oracle for Java 24 availability
- Updated expected test count from 611 to 850 (includes new codegen tests)
- Updated expected skipped count to 2 (recursive schemas in codegen)

The json-java21-jtd-codegen module requires Java 24+ for the ClassFile API (JEP 484).
Previous workflow used Java 21 which caused compilation failure: 'release version 24 not supported'.

Co-authored-by: Simon Massey <simbo1905@users.noreply.github.com>

Author: cursoragent

.github/workflows/ci.yml

@@ -13,11 +13,11 @@ jobs:
       - name: Checkout
         uses: actions/checkout@v4
 
-      - name: Set up JDK 21
+      - name: Set up JDK 24
         uses: actions/setup-java@v4
         with:
-          distribution: temurin
-          java-version: '21'
+          distribution: oracle
+          java-version: '24'
           cache: 'maven'
 
       - name: Build and verify
@@ -39,8 +39,8 @@ jobs:
                       for k in totals: totals[k]+=int(r.get(k,'0'))
                   except Exception:
                       pass
-          exp_tests=611
-          exp_skipped=0
+          exp_tests=850
+          exp_skipped=2
           if totals['tests']!=exp_tests or totals['skipped']!=exp_skipped:
               print(f"Unexpected test totals: {totals} != expected tests={exp_tests}, skipped={exp_skipped}")
               sys.exit(1)