♻️ refactor: 세션 타임아웃 값을 환경변수로 대치

Author: dlsrks1021

backend/src/main/resources/application.yml

@@ -64,5 +64,5 @@ server:
         same-site: None
         secure: true
         http-only: true
-      timeout: 60
+      timeout: ${SESSION_TIMEOUT}