hotfix: validation 의존성 추가

Author: Kim DongMin

build.gradle

@@ -48,6 +48,7 @@ dependencies {
 
 	// Swagger
 	implementation 'org.springdoc:springdoc-openapi-starter-webmvc-ui:2.6.0'
+	implementation 'org.springframework.boot:spring-boot-starter-validation'
 	runtimeOnly 'com.mysql:mysql-connector-j'
 	testCompileOnly 'org.projectlombok:lombok'
 	testAnnotationProcessor 'org.projectlombok:lombok'