test: embedded Redis 초기화를 명시 opt-in으로 분리한다

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

src/test/kotlin/kr/co/vividnext/sodalive/support/SpringBootIntegrationSampleTest.kt

@@ -5,9 +5,11 @@ import org.junit.jupiter.api.Test
 import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.boot.test.context.SpringBootTest
 import org.springframework.data.redis.core.StringRedisTemplate
+import org.springframework.test.context.ContextConfiguration
 import javax.persistence.EntityManager
 
 @SpringBootTest
+@ContextConfiguration(initializers = [EmbeddedRedisInitializer::class])
 class SpringBootIntegrationSampleTest {
     @Autowired
     private lateinit var entityManager: EntityManager

src/test/resources/META-INF/spring.factories

@@ -1,2 +0,0 @@
-org.springframework.context.ApplicationContextInitializer=\
-kr.co.vividnext.sodalive.support.EmbeddedRedisInitializer