Issue when decoding a simple Enum with no member values.

[nuno1212s]

Bincode version: 2.0.0-rc3

I'm facing an issue when using bincode's serde facing serialization/deserialization with simple Enums.
Namely I always get UnexpectedEnd { additional: 1 } error when trying to decode the enum.

The enum in question:

#[derive(Clone, Debug, Serialize, Deserialize, PartialEq, Eq)]
pub enum MessageModule {
    Reconfiguration,
    Protocol,
    StateProtocol,
    Application,
}

The unit test used to verify this behaviour:

#[test]
    pub fn test_message_mod_serialization() -> Result<()> {

        let msg_mod = MessageModule::Protocol;

        let vec = bincode::serde::encode_to_vec(&msg_mod, bincode::config::standard())?;

        let mod_bytes = Bytes::from(vec);

        println!("Mod bytes {:x?}", mod_bytes);

        let (de_ser_msg_mod, msg_mod_size): (MessageModule, usize) = bincode::serde::decode_borrowed_from_slice(mod_bytes.as_ref(), bincode::config::standard())?;

        assert_eq!(de_ser_msg_mod, msg_mod);

        Ok(())
 }

Bytes::from is using the bytes crate.

Expected behaviour: The decoded message module should match the encoded one.
Observed behaviour: Error: UnexpectedEnd { additional: 1 }