updated pipeline to Java 21 and changed distribution to zulu

Author: hollesse

.github/workflows/test.yml

@@ -6,9 +6,9 @@ jobs:
     steps:
       - uses: actions/checkout@v3
       - name: Setup Java JDK
-        uses: actions/setup-java@v3.5.1
+        uses: actions/setup-java@v4.2.1
         with:
-          distribution: 'temurin'
-          java-version: '17'
+          distribution: 'zulu'
+          java-version: '21'
       - name: Build & Test
         run: ./mvnw clean verify