I have this error when I deploy the test but I don´t know why

this my test:

@IsTest
public with sharing class LeadTaskTest {
    @IsTest
      static void createLeadsAndTasksTest(){
         
        //create new lead
        Lead newLead = Build.aLead()
        .withFirstName('rafa2')
        .withLastName('franco2')
        .withDescripcionPersonalizada('description example2')
        .withTextoAuxiliar('aux text2')
        .build();    
           
        Task newTask = Build.aTask()
        .withDescripcionPersonalizada(newLead.Descripcion_Personalizada__c)
        .withTextoAuxiliar(newLead.Texto_Auxiliar__c)
        .withWhoId(newLead);
    Test.startTest();
    insert newLead;
    insert newTask;
    Test.stopTest();
 
    List<Task> tasks = [
        SELECT WhoId, Descripcion_personalizada__c, Texto_auxiliar__c
         FROM Task
         WHERE WhoId = :newLead.id];
    System.assertEquals(1,  tasks.size(),'text');
   
  }
}

this is my handler:

public with sharing class LeadTaskHandler {
   
    public createAndInsertTaskAssociatedLeadHandler(List<Lead> leadList) {
        List<task> listTask = new List<task>();
        for (Lead lead : leadList) {
            /*create a task associated with the lead with fields created
            *Description_Personalized and Text_Auxiliar__c with lead info
            */
            Task newTask = new Task(
                Descripcion_Personalizada__c = lead.Descripcion_Personalizada__c,
                Texto_Auxiliar__c = lead.Texto_Auxiliar__c,
                WhoId = lead.id
            );
           
                     
            listTask.add(newTask);
        }
        insert listTask;
       
    }
}

my trigger: 

trigger LeadTrigger on Lead (before insert, before update, after insert) {
    if (Trigger.isBefore) {
        if (Trigger.isInsert) {
            LeadHandler.leadInsertHandler(Trigger.new);
        }
    }
    if (Trigger.isAfter) {
        if (Trigger.isInsert) {
            LeadTaskHandler.createAndInsertTaskAssociatedLeadHandler(Trigger.new);
        }
    }
}

and my build:

//Generated by BuildGenerator v1.7
@IsTest global class Build {
    /*------------------------------------------------------------------------
                 LeadBuilderStart
    ------------------------------------------------------------------------*/
     public class LeadBuilder {
        private Lead obj = new Lead(LastName = 'STRING',
            Company = 'STRING',
            Status = Lead.Status.getDescribe().getPickListValues().get(0).getValue()
        );
        public LeadBuilder withLastName(String value) {
             obj.LastName = value;
             return this;
        }
        public LeadBuilder withFirstName(String value) {
             obj.FirstName = value;
             return this;
        }
        public LeadBuilder withTextoAuxiliar(String value) {
             obj.Texto_Auxiliar__c = value;
             return this;
        }
        public LeadBuilder withDescripcionPersonalizada(String value) {
             obj.Descripcion_Personalizada__c = value;
             return this;
        }
         public Lead build() {
             return obj;
        }
    }
    public static LeadBuilder aLead() { return new LeadBuilder(); }
    /*------------------------------------------------------------------------
                 LeadBuilderEnd
    ------------------------------------------------------------------------*/
    /*------------------------------------------------------------------------
                 TaskBuilderStart
    ------------------------------------------------------------------------*/
     public class TaskBuilder {
        private Task obj = new Task(Status = 'Not Started',
            Priority = 'High'
        );
        public TaskBuilder withWhoId(Contact value) {
             obj.WhoId = value.Id;
             return this;
        }
        public TaskBuilder withWhoId(Lead value) {
             obj.WhoId = value.Id;
             return this;
        }
        public TaskBuilder withDescripcionPersonalizada(String value) {
             obj.Descripcion_Personalizada__c = value;
             return this;
        }
        public TaskBuilder withTextoAuxiliar(String value) {
             obj.Texto_Auxiliar__c = value;
             return this;
        }
         public Task build() {
             return obj;
        }
    }
    public static TaskBuilder aTask() { return new TaskBuilder(); }
    /*------------------------------------------------------------------------
                 TaskBuilderEnd
    ------------------------------------------------------------------------*/
 
}