Make internal SoapServer/SoapClient state private

This was previously implicitly public due to the use of dynamic
properties. Make this internal state private.

If someone complains, we can consider relaxing this to protected
or public on a case-by-case basis.

ext/soap/soap.stub.php

@@ -55,9 +55,9 @@ public function __construct(mixed $data, ?int $encoding, ?string $typeName = nul
 class SoapServer
 {
     /** @var resource */
-    public $service;
+    private $service;
 
-    public ?SoapFault $__soap_fault = null;
+    private ?SoapFault $__soap_fault = null;
 
     public function __construct(?string $wsdl, array $options = []) {}
 
@@ -91,48 +91,48 @@ public function handle(?string $request = null): void {}
 
 class SoapClient
 {
-    public ?string $uri = null;
-    public ?int $style = null;
-    public ?int $use = null;
-    public ?string $location = null;
-    public bool $trace = false;
-    public ?int $compression = null;
+    private ?string $uri = null;
+    private ?int $style = null;
+    private ?int $use = null;
+    private ?string $location = null;
+    private bool $trace = false;
+    private ?int $compression = null;
     /** @var resource|null */
-    public $sdl = null;
+    private $sdl = null;
     /** @var resource|null */
-    public $typemap = null;
+    private $typemap = null;
     /** @var resource|null */
-    public $httpsocket = null;
+    private $httpsocket = null;
     /** @var resource|null */
-    public $httpurl = null;
-
-    public ?string $_login = null;
-    public ?string $_password = null;
-    public bool $_use_digest = false;
-    public ?string $_digest = null;
-    public ?string $_proxy_host = null;
-    public ?int $_proxy_port = null;
-    public ?string $_proxy_login = null;
-    public ?string $_proxy_password = null;
-    public bool $_exceptions = true;
-    public ?string $_encoding = null;
-    public ?array $_classmap = null;
-    public ?int $_features = null;
-    public int $_connection_timeout = 0;
+    private $httpurl = null;
+
+    private ?string $_login = null;
+    private ?string $_password = null;
+    private bool $_use_digest = false;
+    private ?string $_digest = null;
+    private ?string $_proxy_host = null;
+    private ?int $_proxy_port = null;
+    private ?string $_proxy_login = null;
+    private ?string $_proxy_password = null;
+    private bool $_exceptions = true;
+    private ?string $_encoding = null;
+    private ?array $_classmap = null;
+    private ?int $_features = null;
+    private int $_connection_timeout = 0;
     /** @var resource|null */
-    public $_stream_context = null;
-    public ?string $_user_agent = null;
-    public bool $_keep_alive = true;
-    public ?int $_ssl_method = null;
-    public int $_soap_version;
-    public ?int $_use_proxy = null;
-    public ?array $_cookies = null;
-    public ?array $__default_headers = null;
-    public ?SoapFault $__soap_fault = null;
-    public ?string $__last_request = null;
-    public ?string $__last_response = null;
-    public ?string $__last_request_headers = null;
-    public ?string $__last_response_headers = null;
+    private $_stream_context = null;
+    private ?string $_user_agent = null;
+    private bool $_keep_alive = true;
+    private ?int $_ssl_method = null;
+    private int $_soap_version;
+    private ?int $_use_proxy = null;
+    private ?array $_cookies = null;
+    private ?array $__default_headers = null;
+    private ?SoapFault $__soap_fault = null;
+    private ?string $__last_request = null;
+    private ?string $__last_response = null;
+    private ?string $__last_request_headers = null;
+    private ?string $__last_response_headers = null;
 
     public function __construct(?string $wsdl, array $options = []) {}