bugfix(user): eliminated username form User, UserJpa and DTOs

src/main/java/com/example/apprecetas/user/domain/entity/User.java

@@ -14,7 +14,6 @@ public class User {
     private String surname;
     private String email;
     private String password;
-    private String username;
     private Role role;
 
 }

src/main/java/com/example/apprecetas/user/infrastructure/controller/dto/UserInputDto.java

@@ -23,6 +23,4 @@ public class UserInputDto {
     @Size(min = 8, message = "La contraseña debe tener al menos 8 caracteres")
     private String password;
 
-    private String username;
-
 }

src/main/java/com/example/apprecetas/user/infrastructure/controller/dto/UserOutputDto.java

@@ -13,6 +13,5 @@ public class UserOutputDto {
     private String name;
     private String surname;
     private String email;
-    private String username;
 
 }

src/main/java/com/example/apprecetas/user/infrastructure/repository/mongodb/UserDocument.java

@@ -21,9 +21,6 @@ public class UserDocument {
     private String email;
     private String password;
 
-    @Indexed(unique = true)
-    private String username;
-
     private Role role;