network/litep2p: Update litep2p network backend to version 0.8.1

[lexnv]

This PR updates the litep2p backend to version 0.8.1 from 0.8.0.

• Check the litep2p updates forum post for performance dashboards.
• Check litep2p release notes

The v0.8.1 release includes key fixes that enhance the stability and performance of the litep2p library. The focus is on long-running stability and improvements to polling mechanisms.

Long Running Stability Improvements

This issue caused long-running nodes to reject all incoming connections, impacting overall stability.

Addressed a bug in the connection limits functionality that incorrectly tracked connections due for rejection.

This issue caused an artificial increase in inbound peers, which were not being properly removed from the connection limit count.

This fix ensures more accurate tracking and management of peer connections #286.

Polling implementation fixes

This release provides multiple fixes to the polling mechanism, improving how connections and events are processed:

• Resolved an overflow issue in TransportContext’s polling index for streams, preventing potential crashes (#283).
• Fixed a delay in the manager’s poll_next function that prevented immediate polling of newly added futures (#287).
• Corrected an issue where the listener did not return Poll::Ready(None) when it was closed, ensuring proper signal handling (#285).

Fixed

• manager: Fix connection limits tracking of rejected connections (#286)
• transport: Fix waking up on filtered events from poll_next (#287)
• transports: Fix missing Poll::Ready(None) event from listener (#285)
• manager: Avoid overflow on stream implementation for TransportContext (#283)
• manager: Log when polling returns Ready(None) (#284)

Testing Done

Started kusama nodes running side by side with a higher number of inbound and outbound connections (500).
We previously tested with peers bounded at 50. This testing filtered out the fixes included in the latest release.

With this high connection testing setup, litep2p outperforms libp2p in almost every domain, from performance to the warnings / errors encountered while operating the nodes.

TLDR: this is the version we need to test on kusama validators next

• Litep2p

Repo	Count	Level	Triage report
polkadot-sdk	409	warn	Report .: . to .. Reason: .. Banned, disconnecting. ( Peer disconnected with inflight after backoffs. Banned, disconnecting. )
litep2p	128	warn	Refusing to add known address that corresponds to a different peer ID
litep2p	54	warn	inbound identify substream opened for peer who doesn't exist
polkadot-sdk	7	error	💔 Called on_validated_block_announce with a bad peer ID .*
polkadot-sdk	1	warn	❌ Error while dialing .: .
polkadot-sdk	1	warn	Report .: . to .. Reason: .. Banned, disconnecting. ( Invalid justification. Banned, disconnecting. )

• Libp2p

Repo	Count	Level	Triage report
polkadot-sdk	1023	warn	💔 Ignored block (#.* -- .) announcement from . because all validation slots are occupied.
polkadot-sdk	472	warn	Report .: . to .. Reason: .. Banned, disconnecting. ( Unsupported protocol. Banned, disconnecting. )
polkadot-sdk	379	error	💔 Called on_validated_block_announce with a bad peer ID .*
polkadot-sdk	163	warn	Report .: . to .. Reason: .. Banned, disconnecting. ( Invalid justification. Banned, disconnecting. )
polkadot-sdk	116	warn	Report .: . to .. Reason: .. Banned, disconnecting. ( Peer disconnected with inflight after backoffs. Banned, disconnecting. )
polkadot-sdk	83	warn	Report .: . to .. Reason: .. Banned, disconnecting. ( Same block request multiple times. Banned, disconnecting. )
polkadot-sdk	4	warn	Re-finalized block #.* (.) in the canonical chain, current best finalized is #.
polkadot-sdk	2	warn	Report .: . to .. Reason: .. Banned, disconnecting. ( Genesis mismatch. Banned, disconnecting. )
polkadot-sdk	2	warn	Report .: . to .. Reason: .. Banned, disconnecting. ( Not requested block data. Banned, disconnecting. )
polkadot-sdk	2	warn	Can't listen on .* because: .*
polkadot-sdk	1	warn	❌ Error while dialing .: .

[bkchr]

This comes only when it is terminated and not shutdown gracefully?

[lexnv]

Double checked with a stopped polkadot node and litep2p backend, we don't seem to emit errors here

[michalkucharczyk]

I went quickly over fixes in litep2p - nice work!

[paritytech-cmd-bot-polkadot-sdk]

Created backport PR for stable2407:

• [stable2407] Backport #6484 #6493 with remaining conflicts!

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin backport-6484-to-stable2407
git worktree add --checkout .worktree/backport-6484-to-stable2407 backport-6484-to-stable2407
cd .worktree/backport-6484-to-stable2407
git reset --hard HEAD^
git cherry-pick -x 8bea091ef131c8d962f45d89c28e17ece17bc5b2
git push --force-with-lease

[paritytech-cmd-bot-polkadot-sdk]

Created backport PR for stable2409:

• [stable2409] Backport #6484 #6494 with remaining conflicts!

Please cherry-pick the changes locally and resolve any conflicts.

git fetch origin backport-6484-to-stable2409
git worktree add --checkout .worktree/backport-6484-to-stable2409 backport-6484-to-stable2409
cd .worktree/backport-6484-to-stable2409
git reset --hard HEAD^
git cherry-pick -x 8bea091ef131c8d962f45d89c28e17ece17bc5b2
git push --force-with-lease