The reason to do a wildcard import of the prelude instead of something
like
// src/observability/prelude.rs
pub(crate) use tracing::*;
// elsewhere
use crate::observability::prelude as o;
o::warn!("something");
is that we can't import traits like tracing::Instrument that way.
I'm generally not a fan of wildcard imports, but I think it can be okay
when it's a module in the same crate. There aren't really an backwards
compatibility hazards because it's your own code.
