fix: team leader join 방식 변경(left join)

Author: daeun084

src/main/kotlin/gat_be/dev/domain/team/repository/TeamRepository.kt

@@ -18,7 +18,7 @@ interface TeamRepository: JpaRepository<Team, Long> {
 
     @Query("SELECT t " +
             "FROM Team t " +
-            "JOIN FETCH t.leader " +
+            "LEFT JOIN FETCH t.leader " +
             "JOIN FETCH t.techStackList " +
             "WHERE t.teamId IN :teamIdList"
     )
@@ -49,7 +49,7 @@ interface TeamRepository: JpaRepository<Team, Long> {
 
     @Query("SELECT t " +
             "FROM Team t " +
-            "JOIN FETCH t.leader " +
+            "LEFT JOIN FETCH t.leader " +
             "JOIN FETCH t.techStackList tsl " +
             "WHERE t.teamId IN :teamIdList" )
     fun findByIdList(