memcached 3.2.0 needed on PHP 8.1 to fix floats stored as negatives

Pretty nasty bug in PHP 8:

https://github.com/php-memcached-dev/php-memcached/issues/500

Was recently fixed on:

https://github.com/php-memcached-dev/php-memcached/releases/tag/v3.2.0

If we can bump memcached to 3.2.0 from 3.1.5 it has right now?