transport/manager: Investigate different state for a dial failure

[lexnv]

Substrate panic triggered on debug_assert:

Thread 'tokio-runtime-worker' panicked at 'assertion failed: false', /usr/local/cargo/registry/src/index.crates.io-6f17d22bba15001f/litep2p-0.6.2/src/transport/manager/mod.rs:748

Code path:

litep2p/src/transport/manager/mod.rs

Lines 738 to 750 in a27d007

	state => {
	tracing::warn!(
	target: LOG_TARGET,
	?peer,
	?connection_id,
	?state,
	"invalid state for dial failure",
	);
	context.state = state;
	debug_assert!(false);
	Ok(())
	}

Substrate issue: paritytech/polkadot-sdk#5595
Grafana link: https://grafana.teleport.parity.io/goto/sR83XkeSg?orgId=1