minor #20885 [HttpFoundation] Add FrankenPHP docs for X-Sendfile (dunglas)

This PR was submitted for the 7.3 branch but it was merged into the 6.4 branch instead.

Discussion
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[HttpFoundation] Add FrankenPHP docs for X-Sendfile

Add link to [FrankenPHP docs](https://frankenphp.dev/docs/x-sendfile/) for `X-Sendfile`.

Commits
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0ce5ffb [HttpFoundation] Add FrankenPHP docs for X-Sendfile

Author: javiereguiluz

components/http_foundation.rst

@@ -854,7 +854,7 @@ Alternatively, if you are serving a static file, you can use a
 
 The ``BinaryFileResponse`` will automatically handle ``Range`` and
 ``If-Range`` headers from the request. It also supports ``X-Sendfile``
-(see for `nginx`_ and `Apache`_). To make use of it, you need to determine
+(see for `FrankenPHP`_, `nginx`_ and `Apache`_). To make use of it, you need to determine
 whether or not the ``X-Sendfile-Type`` header should be trusted and call
 :method:`Symfony\\Component\\HttpFoundation\\BinaryFileResponse::trustXSendfileTypeHeader`
 if it should::
@@ -1061,6 +1061,7 @@ Learn More
     /session
     /http_cache/*
 
+.. _FrankenPHP: https://frankenphp.dev/docs/x-sendfile/
 .. _nginx: https://mattbrictson.com/blog/accelerated-rails-downloads
 .. _Apache: https://tn123.org/mod_xsendfile/
 .. _`JSON Hijacking`: https://haacked.com/archive/2009/06/25/json-hijacking.aspx/