/usr/share/php/GuzzleHttp/Promise/ is in php-guzzlehttp-promises 1.0.3-1build1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/php/GuzzleHttp/Promise/AggregateException.php
/usr/share/php/GuzzleHttp/Promise/CancellationException.php
/usr/share/php/GuzzleHttp/Promise/EachPromise.php
/usr/share/php/GuzzleHttp/Promise/FulfilledPromise.php
/usr/share/php/GuzzleHttp/Promise/Promise.php
/usr/share/php/GuzzleHttp/Promise/PromiseInterface.php
/usr/share/php/GuzzleHttp/Promise/PromisorInterface.php
/usr/share/php/GuzzleHttp/Promise/RejectedPromise.php
/usr/share/php/GuzzleHttp/Promise/RejectionException.php
/usr/share/php/GuzzleHttp/Promise/TaskQueue.php
/usr/share/php/GuzzleHttp/Promise/autoload.php
/usr/share/php/GuzzleHttp/Promise/functions.php
/usr/share/php/GuzzleHttp/Promise/functions_include.php