Fix docker build issue

Dockerfile

@@ -3,6 +3,7 @@ FROM eclipse-temurin:21.0.6_7-jdk-alpine AS build
 COPY .mvn/ .mvn
 COPY mvnw pom.xml ./
 COPY src ./src
+COPY checkstyle.xml ./
 
 RUN ["chmod", "+x", "./mvnw"]
 RUN ./mvnw install