WordPress “timing out” During Updates

where are you hosting?

So you’re doing this on a VPS. Try increasing the curl timeout in /etc/php.ini. It defaults to 60, try 300.

; Default timeout for socket based streams (seconds)
; http://php.net/default-socket-timeout
default_socket_timeout = 300

YOu may need to restart php-fpm and your web service after making the change.

what happens if you try

wget https://ww.wp.xz.cn/latest.tar.gz

from the command line?

Are there any errors in your logs? Maybe /var/www/php-fpm/error.log?

Interesting header when inspecting your site: x-powered-by:PHP/5.5.9-1ubuntu4.22

You really ought to be using PHP 7.