Update used java version

Author: Joltras

.github/workflows/main-build.yml

@@ -26,6 +26,6 @@ jobs:
         uses: actions/setup-java@v5
         with:
           distribution: temurin
-          java-version: 21
+          java-version: 24
       - name: Build on ${{ matrix.os }}
         run: ./gradlew test