Prem Chaitanya Prathi 50deb8f188
chore: migrate to libp2p_mix package
Mix has been extracted from nim-libp2p into its own package at
logos-co/nim-libp2p-mix. Update all imports of libp2p/protocols/mix*
to use libp2p_mix*, add the new package as a vendored submodule and
nimble dep, and bump the mix-rln-spam-protection-plugin submodule to
its corresponding migration branch.

Verified end-to-end with simulations/mixnet (5-node mixnet + chat2mix):
- All 5 wakunode2 instances mount /mix/1.0.0 successfully
- RLN spam-protection loads and registers
- chat2mix publishes via lightpush with mixify=true
- Cover traffic runs at the configured 20s interval
2026-04-30 21:52:57 +05:30
..
2025-09-11 20:40:01 +05:30