8 files declare their use of FileUploadSanitizeNameEvent

CKEditor5ImageController.php in core/modules/ckeditor5/src/Controller/CKEditor5ImageController.php
file.module in core/modules/file/file.module
Defines a "managed_file" Form API field and a "file" field for Field module.
FileUploadHandler.php in core/modules/file/src/Upload/FileUploadHandler.php
FileUploadResource.php in core/modules/file/src/Plugin/rest/resource/FileUploadResource.php
FileUploadSanitizeNameEventTest.php in core/tests/Drupal/Tests/Core/File/FileUploadSanitizeNameEventTest.php
SecurityFileUploadEventSubscriber.php in core/modules/system/src/EventSubscriber/SecurityFileUploadEventSubscriber.php
SecurityFileUploadEventSubscriberTest.php in core/modules/system/tests/src/Unit/Event/SecurityFileUploadEventSubscriberTest.php
TemporaryJsonapiFileFieldUploader.php in core/modules/jsonapi/src/Controller/TemporaryJsonapiFileFieldUploader.php

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