Remove deprecated Certificate contact_id field (#164)

The `contact_id` field in the Certificate schema was deprecated on
2022-05-17 and is no longer required for certificate operations. Remove
`contactId` from the `Certificate` struct.

This is a breaking change.

References dnsimple/dnsimple-developer#987

Author: weppos

CHANGELOG.md

@@ -6,6 +6,7 @@ This project uses [Semantic Versioning 2.0.0](http://semver.org/), the format is
 
 ### Removed
 
+- **BREAKING**: Removed the deprecated `contactId` field from the `Certificate` struct. The field was deprecated on 2022-05-17 and is no longer required for certificate operations.
 - **BREAKING**: Removed the deprecated `from` and `to` fields from the `EmailForward` struct. Use `aliasEmail` and `destinationEmail` instead.
 
 ## 6.3.0 - 2026-04-15

src/Dnsimple/Struct/Certificate.php

@@ -17,11 +17,6 @@ class Certificate
      * @var int The associated domain ID
      */
     public $domainId;
-    /**
-     * @var int The associated contact ID
-     * @deprecated
-     */
-    public $contactId;
     /**
      * @var string The certificate name
      */
@@ -71,7 +66,6 @@ public function __construct($data)
     {
         $this->id = $data->id;
         $this->domainId = $data->domain_id;
-        $this->contactId = $data->contact_id;
         $this->name = $data->name;
         $this->commonName = $data->common_name;
         $this->years = $data->years;

tests/Dnsimple/Service/CertificatesTest.php

@@ -71,7 +71,6 @@ public function testGetCertificate()
 
         self::assertEquals(101967, $certificate->id);
         self::assertEquals(289333, $certificate->domainId);
-        self::assertEquals(2511, $certificate->contactId);
         self::assertEquals("www", $certificate->name);
         self::assertEquals("www.bingo.pizza", $certificate->commonName);
         self::assertEquals(1, $certificate->years);