Merge branch '6.4' into 7.0

* 6.4:
  [Form] Fix merging form data and files (ter)
  [Intl] Update the ICU data to 74.1
  [Scheduler] Use MockClock
  [AssetMapper] Fixing memory bug where we stored way more file content than needed
  [AssetMapper] jsdelivr "no version" import syntax
  [HtmlSanitizer] Consider `width` attribute as safe
  [DoctrineBridge] Fix exception message
  [Security][Validator] Missing translations for Luxembourgish

Author: fabpot

Reference/W3CReference.php

@@ -394,7 +394,7 @@ final class W3CReference
         'vlink' => false,
         'vspace' => true,
         'webkitdirectory' => true,
-        'width' => false,
+        'width' => true,
         'wrap' => true,
     ];
 }

Tests/HtmlSanitizerAllTest.php

@@ -427,8 +427,8 @@ public static function provideSanitizeBody()
                 '<hr />',
             ],
             [
-                '<img src="/img/example.jpg" alt="Image alternative text" title="Image title">',
-                '<img src="/img/example.jpg" alt="Image alternative text" title="Image title" />',
+                '<img src="/img/example.jpg" alt="Image alternative text" title="Image title" height="150" width="300">',
+                '<img src="/img/example.jpg" alt="Image alternative text" title="Image title" height="150" width="300" />',
             ],
             [
                 '<img src="http://trusted.com/img/example.jpg" alt="Image alternative text" title="Image title" />',