fix: removed contradictive @NotNull preventing to add data to database.

MyINPulse-back/src/main/java/enseirb/myinpulse/model/Annotation.java

@@ -1,14 +1,12 @@
 package enseirb.myinpulse.model;
 
 import jakarta.persistence.*;
-import jakarta.validation.constraints.NotNull;
 
 @Entity
 @Table(name = "annotation")
 public class Annotation {
 
     @Id
-    @NotNull
     @GeneratedValue(strategy = GenerationType.IDENTITY)
     private Long idAnnotation;