Fix build

Author: Kenny-Hui

.github/workflows/build.yml

@@ -14,10 +14,10 @@ jobs:
         uses: actions/checkout@v4
       - name: Validate gradle wrapper
         uses: gradle/actions/wrapper-validation@v3
-      - name: Setup JDK 17
+      - name: Setup JDK 21
         uses: actions/setup-java@v4
         with:
-          java-version: 17
+          java-version: 21
           distribution: 'temurin'
       - name: Make gradle wrapper executable
         run: chmod +x ./gradlew