Update lading_payload fuzz tests to functional state

This commit updates our fuzz tests to the point where they are functional. I have not
not otherwise made changes that are not mechanically motivated.

Signed-off-by: Brian L. Troutwine <brian.troutwine@datadoghq.com>

Author: blt

Cargo.lock

@@ -223,6 +223,7 @@ impl LogrotateFS {
 }
 
 #[tracing::instrument(skip(state))]
+#[allow(clippy::similar_names)] // ctime and crtime are standard Unix file time names
 fn getattr_helper(
     state: &mut MutexGuard<model::State>,
     start_time_system: std::time::SystemTime,