Apply spotless plugin rules

Author: vietj

.github/workflows/ci.yml

@@ -26,4 +26,4 @@ jobs:
           java-version: ${{ inputs.jdk }}
           distribution: temurin
       - name: Run tests
-        run: mvn -s .github/maven-ci-settings.xml -q clean verify -B
+        run: mvn -s .github/maven-ci-settings.xml -q clean verify -B -Pcheckstyle