Add credential repository testing

src/main/java/com/faf223/expensetrackerfaf/model/Credential.java

@@ -2,6 +2,7 @@ package com.faf223.expensetrackerfaf.model;
 
 import jakarta.persistence.*;
 import lombok.AllArgsConstructor;
+import lombok.Builder;
 import lombok.Data;
 import lombok.NoArgsConstructor;
 
@@ -9,6 +10,7 @@ import lombok.NoArgsConstructor;
 @Entity(name = "credentials")
 @NoArgsConstructor
 @AllArgsConstructor
+@Builder
 public class Credential {
     @Id
     @GeneratedValue(strategy = GenerationType.IDENTITY)

src/main/java/com/faf223/expensetrackerfaf/model/User.java

@@ -34,8 +34,6 @@
         private String username;
 
         @Transient
-    //    @NotNull(message = "Password must not be null")
-    //    @NotEmpty(message = "Password must not be empty")
         private String password;
 
         @OneToMany(mappedBy = "user", fetch = FetchType.LAZY, cascade = CascadeType.ALL)