fix(IssueField): make labels nullable and remove default value initialization (#73)

Updated the 'labels' property in the IssueField class to be nullable and removed its default value initialization in the constructor. This change was necessary to prevent a issue that empty the labels in Jira if you don´t set any label

Co-authored-by: Matheus Perusso <matheus@ixcsoft.com.br>

Author: mperusso

src/Issue/IssueField.php

@@ -35,7 +35,7 @@ class IssueField implements \JsonSerializable
 
     public ?IssueStatus $status = null;
 
-    public array $labels;
+    public ?array $labels = null;
 
     public Project $project;
 
@@ -102,8 +102,6 @@ class IssueField implements \JsonSerializable
 
     public function __construct($updateIssue = false)
     {
-        $this->labels = [];
-
         if ($updateIssue !== true) {
             $this->project = new \JiraCloud\Project\Project();