Timezone and locale need to be set

[UntouchedWagons]

The timezone and locale is set to UTC and C.UTF-8 by default. This shouldn't be a critical problem but could cause cron and keyboard-related issues.

[UntouchedWagons]

Setting the locale via CloudInit for Debian 13 seems to be broken at the moment, see canonical/cloud-init#6471 and referenced pull request.