transport/manager: Investigate connection closed for a nonexistent peer

[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/protocol/transport_service.rs:220

Code path: https://github.com/paritytech/litep2p/blob/a27d0072913be67cce904e2e8c465cc37ec5223a/src/protocol/transport_service.rs#L212-L222

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