transport/manager: Investigate connection closed without primary and secondary connections

[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:858

Code path:

litep2p/src/transport/manager/mod.rs

Lines 850 to 859 in a27d007

	None => {
	tracing::warn!(
	target: LOG_TARGET,
	?peer,
	?connection_id,
	"non-primary connection was closed but secondary connection doesn't exist",
	);
	debug_assert!(false);
	Err(Error::InvalidState)

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