Merge branch 'be/registration' into 'backend'

feat: registration cascade 옵션 추가

See merge request s11-webmobile1-sub2/S11P12A701!149

backend/src/main/java/com/edufocus/edufocus/registration/entity/Registration.java

@@ -22,11 +22,11 @@ public class Registration {
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private long id;
 
-    @ManyToOne
+    @ManyToOne(cascade = CascadeType.ALL)
     @JoinColumn(name = "user_id")
     private User user;
 
-    @ManyToOne
+    @ManyToOne(cascade = CascadeType.ALL)
     @JoinColumn(name = "lecture_id")
     private Lecture lecture;