I am trying to use an Apex Class I found at this link: https://automationchampion.com/2020/12/01/getting-started-with-process-builder-part-50-auto-convert-leads/ Here is the Apex Class:

Public class AutoConvertLeads 
{     @InvocableMethod   
    public static void LeadAssign(List<Id> LeadIds)  
    {         
        LeadStatus CLeadStatus= [SELECT Id, MasterLabel FROM LeadStatus WHERE IsConverted=true Limit 1];    
        List<Database.LeadConvert> MassLeadconvert = new List<Database.LeadConvert>();    
        for(id currentlead: LeadIds){                
            Database.LeadConvert Leadconvert = new Database.LeadConvert();    
            Leadconvert.setLeadId(currentlead);                               
            Leadconvert.setConvertedStatus(CLeadStatus.MasterLabel);             
            Leadconvert.setDoNotCreateOpportunity(TRUE); //Remove this line if you want to create an opportunity from Lead Conversion  
            MassLeadconvert.add(Leadconvert);    
        }                  
        if (!MassLeadconvert.isEmpty())
        {            
            List<Database.LeadConvertResult> lcr = Database.convertLead(MassLeadconvert);       
        }    
    } 
}

Here is the Test Class

@isTest 
      public class TestAutoConvertLeads{
      static testMethod void createnewlead() {
      User userToCreate = [Select id from user where profile.name='System Administrator' Limit 1];
      
      Test.startTest();    
      Lead leadToCreate =new Lead();
      List<id> Ids= New List<Id>();
      leadToCreate.ownerid= userToCreate.id;
      leadToCreate.LastName ='Gupta';
      leadToCreate.Company='Salesforce';
      leadToCreate.LeadSource='Partner Referral';
      leadToCreate.Rating='';
      leadToCreate.Status='';
      insert leadToCreate; 
      
      Ids.add(leadToCreate.id);
      AutoConvertLeads.LeadAssign(Ids);
      
      Test.stopTest();
   }
}

Here is the error I get when trying to bring in the Inbound Change set to my production org when running the Test Class test:

"createnewlead - - - Methods defined as TestMethod do not support Web service callouts Stack Trace: null"