ext/uri: Remove dead Uri\WhatWg\Url::getFragment() method implementation (#23303)

https://github.com/php/php-src/pull/18836/changes#diff-36685c80eb4c9b461c87f9f56845f1ad5f166f7e26d4e783b0511a1c670d8172R177 registered Uri\WhatWg\Url::getFragment() as an "implementation-alias", then https://github.com/php/php-src/pull/19636/changes#diff-80838f0d9bf6078a847dbafc2fff787d67013a7f19461cb6508246b5413fb4dfR900 added other aliases but also added the `getFragment()` method implementation back without removing its alias, which left it unused. So I am once again removing it here.

Author: NickSdot

ext/uri/php_uri.c

@@ -968,11 +968,6 @@ PHP_METHOD(Uri_WhatWg_Url, getHostType)
 	php_uri_parser_whatwg_host_type_read(uri_object->uri, return_value);
 }
 
-PHP_METHOD(Uri_WhatWg_Url, getFragment)
-{
-	php_uri_property_read_helper(INTERNAL_FUNCTION_PARAM_PASSTHRU, PHP_URI_PROPERTY_NAME_FRAGMENT, PHP_URI_COMPONENT_READ_MODE_NORMALIZED_UNICODE);
-}
-
 PHP_METHOD(Uri_WhatWg_Url, equals)
 {
 	zend_object *that_object;