ci: update workflow to test on JDKs 22,25,26 (Linux)

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: dfa1

.github/workflows/ci.yml

@@ -8,24 +8,29 @@ on:
 
 jobs:
   build:
+    name: Build (Java ${{ matrix.java-version }})
     runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        java-version: [22, 25, 26]
 
     steps:
       - uses: actions/checkout@v4
 
-      - name: Set up Azul Zulu JDK 25
+      - name: Set up JDK ${{ matrix.java-version }}
         uses: actions/setup-java@v4
         with:
-          distribution: zulu
-          java-version: '25'
+          distribution: 'zulu'
+          java-version: ${{ matrix.java-version }}
+          cache: 'maven'
 
       - name: Cache Maven repository
         uses: actions/cache@v4
         with:
           path: ~/.m2/repository
-          key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}
+          key: ${{ runner.os }}-maven-${{ hashFiles('**/pom.xml') }}-${{ matrix.java-version }}
           restore-keys: |
-            ${{ runner.os }}-maven-
+            ${{ runner.os }}-maven-${{ matrix.java-version }}-
 
       - name: Install protobuf compiler
         run: sudo apt-get install -y protobuf-compiler