Merge branch 'reintroduce-multi-thread' into 'master'

Reintroduce multi-threaded Duo Chat

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/183526



Merged-by: Artur Fedorov <afedorov@gitlab.com>
Approved-by: Frédéric Caplette <fcaplette@gitlab.com>
Approved-by: Artur Fedorov <afedorov@gitlab.com>
Reviewed-by: David Pisek <dpisek@gitlab.com>
Reviewed-by: Frédéric Caplette <fcaplette@gitlab.com>
Reviewed-by: Jannik Lehmann <jlehmann@gitlab.com>
Reviewed-by: Artur Fedorov <afedorov@gitlab.com>
Co-authored-by: Jannik Lehmann <jlehmann@gitlab.com>