v6.4.19

Changelog (v6.4.18...v6.4.19)

• bug symfony/symfony#59763 [HttpClient] Don't send any default content-type when the body is empty (@nicolas-grekas)
• bug symfony/symfony#59727 [HttpClient] Fix activity tracking leading to negative timeout errors (@nicolas-grekas)
• bug symfony/symfony#59689 [HttpClient] Fix buffering AsyncResponse with no passthru (@nicolas-grekas)
• bug symfony/symfony#59654 [HttpClient] Fix uploading files > 2GB (@nicolas-grekas)