Ignore the 'instant is unmaintained' advisory. (#16763)

# Objective

- Hides #16477.

## Solution

Add the advisory ID to the list of ignored advisories.

The notify-types crate has already been switched to web-time upstream,
but it's up to the maintainer to publish the crate. There is nothing for
us to do, so better to just ignore it so we don't ignore this CI check
anymore (and mistakenly miss new advisories).

## Testing

- Tested locally.

deny.toml

@@ -3,7 +3,10 @@ all-features = true
 
 [advisories]
 version = 2
-ignore = []
+ignore = [
+  # TODO: #16477 - Delete this once notify-types has been bumped.
+  "RUSTSEC-2024-0384",
+]
 
 [licenses]
 version = 2