Refactor CI to use matrix strategy and add JDK 24 support (#895)

- Replace individual JDK test jobs with a single matrix-based job
- Add JDK 24 to the test matrix (now tests JDK 8, 11, 17, 21, and 24)
- Simplifies CI configuration and makes it easier to add new JDK versions

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-authored-by: Claude <[email protected]>

Author: xerial

.github/workflows/CI.yml

@@ -27,75 +27,25 @@ jobs:
       - uses: actions/checkout@v4
       - name: jcheckstyle
         run: ./sbt jcheckStyle
-  test_jdk21:
-    name: Test JDK21
+  
+  test:
+    name: Test JDK${{ matrix.java }}
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        java: ['8', '11', '17', '21', '24']
     steps:
       - uses: actions/checkout@v4
       - uses: actions/setup-java@v4
         with:
           distribution: 'zulu'
-          java-version: '21'
+          java-version: ${{ matrix.java }}
       - uses: actions/cache@v4
         with:
           path: ~/.cache
-          key: ${{ runner.os }}-jdk21-${{ hashFiles('**/*.sbt') }}
-          restore-keys: ${{ runner.os }}-jdk21-
+          key: ${{ runner.os }}-jdk${{ matrix.java }}-${{ hashFiles('**/*.sbt') }}
+          restore-keys: ${{ runner.os }}-jdk${{ matrix.java }}-
       - name: Test
         run: ./sbt test
       - name: Universal Buffer Test
-        run: ./sbt test -J-Dmsgpack.universal-buffer=true
-  test_jdk17:
-    name: Test JDK17
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-java@v4
-        with:
-          distribution: 'zulu'
-          java-version: '17'
-      - uses: actions/cache@v4
-        with:
-          path: ~/.cache
-          key: ${{ runner.os }}-jdk17-${{ hashFiles('**/*.sbt') }}
-          restore-keys: ${{ runner.os }}-jdk17-
-      - name: Test
-        run: ./sbt test
-      - name: Universal Buffer Test
-        run: ./sbt test -J-Dmsgpack.universal-buffer=true
-  test_jdk11:
-    name: Test JDK11
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-java@v4
-        with:
-          distribution: 'zulu'
-          java-version: '11'
-      - uses: actions/cache@v4
-        with:
-          path: ~/.cache
-          key: ${{ runner.os }}-jdk11-${{ hashFiles('**/*.sbt') }}
-          restore-keys: ${{ runner.os }}-jdk11-
-      - name: Test
-        run: ./sbt test
-      - name: Universal Buffer Test
-        run: ./sbt test -J-Dmsgpack.universal-buffer=true
-  test_jdk8:
-    name: Test JDK8
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - uses: actions/setup-java@v4
-        with:
-          distribution: 'zulu'
-          java-version: '8'
-      - uses: actions/cache@v4
-        with:
-          path: ~/.cache
-          key: ${{ runner.os }}-jdk8-${{ hashFiles('**/*.sbt') }}
-          restore-keys: ${{ runner.os }}-jdk8-
-      - name: Test
-        run: ./sbt test
-      - name: Universal    Buffer Test
-        run: ./sbt test -J-Dmsgpack.universal-buffer=true
+        run: ./sbt test -J-Dmsgpack.universal-buffer=true