[Fix] tss signature is missing

[Marca23]

Fixed: prevent relayer panics when TSS signing or packet data is missing

Implementation details

• Alert when TSS is missing
• Skip packets with missing TSS for all non-EVM chains

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[Copilot]

Pull request overview

This PR hardens TunnelRelayer.getTunnelPacket against panics/loops caused by missing TSS signing data. Previously, falling back from CurrentGroupSigning to IncomingGroupSigning could overwrite a usable signing with nil, and a not-success status on a non-EVM chain would cause the same sequence to be retried indefinitely.

Changes:

• Only swap signing to IncomingGroupSigning when the incoming value is non-nil.
• Emit an alert and return an error when no signing info is available at all.
• On a non-success signing status, advance lastRelayedSequence/lastRelayedAt for non-EVM chains so the packet is skipped on subsequent rounds.

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