[Improve/#29] Elasticsearch 버전 호환성 문제 해결 (#30)

* improve: Elasticsearch 8.18.0으로 버전 업그레이드

* improve: Elasticsearch 메모리 설정 최적화

Author: Dimo-2562

docker-compose.yml

@@ -32,7 +32,7 @@ services:
       - redis-data:/data
 
   elasticsearch:
-    image: docker.elastic.co/elasticsearch/elasticsearch:8.11.0
+    image: docker.elastic.co/elasticsearch/elasticsearch:8.18.0
     container_name: tech-fork-elasticsearch
     restart: always
     ports:
@@ -41,7 +41,7 @@ services:
     environment:
       - discovery.type=single-node
       - xpack.security.enabled=false
-      - "ES_JAVA_OPTS=-Xms1g -Xmx1g"
+      - "ES_JAVA_OPTS=-Xms512m -Xmx512m"
     networks:
       - app-network
     volumes: