Merge branch '6.4' into 7.2

* 6.4:
  fix EmojiTransliterator return type compatibility with PHP 8.5
  Bump Symfony version to 6.4.22
  Update VERSION for 6.4.21
  Update CONTRIBUTORS for 6.4.21
  Update CHANGELOG for 6.4.21
  Fix return type is non-nullable
  Fix overwriting an array element

Author: xabbuh

Tests/RequestTest.php

@@ -589,7 +589,6 @@ public function testGetUri()
 
         $server['REDIRECT_QUERY_STRING'] = 'query=string';
         $server['REDIRECT_URL'] = '/path/info';
-        $server['SCRIPT_NAME'] = '/index.php';
         $server['QUERY_STRING'] = 'query=string';
         $server['REQUEST_URI'] = '/path/info?toto=test&1=1';
         $server['SCRIPT_NAME'] = '/index.php';
@@ -716,7 +715,6 @@ public function testGetUriForPath()
 
         $server['REDIRECT_QUERY_STRING'] = 'query=string';
         $server['REDIRECT_URL'] = '/path/info';
-        $server['SCRIPT_NAME'] = '/index.php';
         $server['QUERY_STRING'] = 'query=string';
         $server['REQUEST_URI'] = '/path/info?toto=test&1=1';
         $server['SCRIPT_NAME'] = '/index.php';