Description

Remove the experimental-discv5 feature flag and make discv5 support a standard part of the networking stack. Additionally, enable discv5 by default alongside discv4.

Current state

The feature flag is currently defined in:

• cmd/ethrex/Cargo.toml (line 106)
• crates/networking/p2p/Cargo.toml (line 75)

It guards the aes-gcm and hkdf dependencies and is enabled by default in ethrex-p2p.

Currently, discv5 must be explicitly enabled via CLI flag (--discovery.discv5).

Tasks

• Remove experimental-discv5 feature flag from cmd/ethrex/Cargo.toml
• Remove experimental-discv5 feature flag from crates/networking/p2p/Cargo.toml
• Make aes-gcm and hkdf regular dependencies
• Remove conditional compilation (#[cfg(feature = "experimental-discv5")]) throughout the codebase
• Enable discv5 by default (both discv4 and discv5 run simultaneously)
• Update CLI flags to allow disabling protocols rather than enabling them