i got this from `postcard-rpc` when my app terminated:
```
WARN  postcard_rpc::host_client::util] Receiver Closed, this could be bad
```
i do roughly the same as in this example (i.e. `select!` on postcard + a `run` function which does something and then terminates after which the whole application terminates): https://github.com/jamesmunns/postcard-rpc/blob/main/example/workbook-host/src/bin/comms-01.rs

do i need to explicitly call `client.close()` after the `select!`? (if so: shouldn't the examples do this as well? i just found the API by looking at the code)