message: implement clippy suggestion to use `or_insert_with`
diff: @@ -570,7 +570,7 @@ impl<'a> EncodeState<'a> {
  for id in resolve.iter() {
  let slot = map
  .entry(id.name())
  - .or_insert(HashMap::new())
  + .or_insert_with(HashMap::new)
  .entry(id.version())
  .or_insert(0);
  *slot += 1;
  