Plugin 'org.springframework.boot:spring-boot-maven-plugin:' not found

해결방법: pom.xml 파일 확인 및 변경

<parent>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-parent</artifactId>
	<version>2.7.9</version>
	<relativePath/> <!-- lookup parent from repository -->
</parent>

<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<version>${parent.version}</version>

• 스프링부트와 스프링부트 메이븐 플러그인의 버전을 맞춰준다.
  spring-boot-starter-parent
spring-boot-maven-plugin