Update build.yml

Author: SpaceWalkerRS

.github/workflows/build.yml

@@ -16,7 +16,7 @@ jobs:
       - uses: actions/setup-java@v4
         with:
           distribution: 'temurin'
-          java-version: '17'
+          java-version: '21'
 
       - name: validate gradle wrapper
         uses: gradle/actions/wrapper-validation@v4