This feature went through a few iterations. At some point,
a `(local timezone/time: unknown)` suffix was part of the
`baibot_now_utc` variable (hoping it improves the model's awareness that
it doesn't know the current local time), but the suffix was ultimately removed
as unnecessary.
Fixes https://github.com/etkecc/baibot/issues/10
This also includes them in the default prompts (for newly-created agents),
so that people can get a better experience out of the box.
