minor #15880 [HttpClient] Update http client testing section (JohnstonCode)

This PR was squashed before being merged into the 4.4 branch.

Discussion
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[HttpClient] Update http client testing section

I have remove all references to MockResponse::getRequestMethod and MockResponse::getRequestUrl as these were added in 5.2

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Commits
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c86e957 [HttpClient] Update http client testing section

Author: javiereguiluz

http_client.rst

@@ -1472,8 +1472,6 @@ Testing Request Data
 
 The ``MockResponse`` class comes with some helper methods to test the request:
 
-* ``getRequestMethod()`` - returns the HTTP method;
-* ``getRequestUrl()`` - returns the URL the request would be sent to;
 * ``getRequestOptions()`` - returns an array containing other information about
   the request such as headers, query parameters, body content etc.
 
@@ -1489,12 +1487,6 @@ Usage example::
         ],
     ]);
 
-    $mockResponse->getRequestMethod();
-    // returns "DELETE"
-
-    $mockResponse->getRequestUrl();
-    // returns "https://example.com/api/article/1337"
-
     $mockResponse->getRequestOptions()['headers'];
     // returns ["Accept: */*", "Authorization: Basic YWxhZGRpbjpvcGVuc2VzYW1l"]
 
@@ -1568,8 +1560,6 @@ test it in a real application::
             $responseData = $service->createArticle($requestData);
 
             // Assert
-            self::assertSame('POST', $mockResponse->getRequestMethod());
-            self::assertSame('https://example.com/api/article', $mockResponse->getRequestUrl());
             self::assertContains(
                 'Content-Type: application/json',
                 $mockResponse->getRequestOptions()['headers']