build: Dockerfile expose 변경

`#` 80, 8080, custom service port

BREAKING-CHANGE: 이전 버전 전환시 eks 동작하지 않음

Author: laigasus

Dockerfile

@@ -12,4 +12,5 @@ FROM openjdk:21-slim
 COPY --from=builder /app/build/libs/core-gateway.jar .
 
 ENTRYPOINT ["java", "-jar", "core-gateway.jar"]
-EXPOSE 8080
+EXPOSE 8080
+EXPOSE 80