chore: use pow for bsc p2p example (paradigmxyz#13380)

crates/net/network/src/config.rs

@@ -266,6 +266,17 @@ impl<N: NetworkPrimitives> NetworkConfigBuilder<N> {
         self
     }
 
+    /// Configures the network to use proof-of-work.
+    ///
+    /// This effectively allows block propagation in the `eth` sub-protocol, which has been
+    /// soft-deprecated with ethereum `PoS` after the merge. Even if block propagation is
+    /// technically allowed, according to the eth protocol, it is not expected to be used in `PoS`
+    /// networks and peers are supposed to terminate the connection if they receive a `NewBlock`
+    /// message.
+    pub const fn with_pow(self) -> Self {
+        self.network_mode(NetworkMode::Work)
+    }
+
     /// Sets the highest synced block.
     ///
     /// This is used to construct the appropriate [`ForkFilter`] and [`Status`] message.

examples/bsc-p2p/src/main.rs

@@ -55,6 +55,8 @@ async fn main() {
     // The network configuration
     let mut net_cfg = NetworkConfig::builder(secret_key)
         .listener_addr(local_addr)
+        // we need to explicitly set the network mode to PoW to allow block propagation, see docs
+        .with_pow()
         .build_with_noop_provider(bsc_chain_spec())
         .set_discovery_v4(
             Discv4ConfigBuilder::default()