Use XorShiftRng to generate non-zero payload

Cargo.toml

@@ -79,6 +79,7 @@ libp2p = { version = "0.51.3", features = [
     "quic",
 ]}
 quickcheck = "1.0.3"
+rand_xorshift = "0.3.0"
 sc-network = "0.28.0"
 sc-utils = "8.0.0"
 serde_json = "1.0.108"

tests/protocol/request_response.rs

@@ -36,6 +36,8 @@ use litep2p::{
 use futures::{channel, StreamExt};
 use multiaddr::{Multiaddr, Protocol};
 use multihash::Multihash;
+use rand::{Rng, SeedableRng};
+use rand_xorshift::XorShiftRng;
 use tokio::time::sleep;
 
 use std::{
@@ -2582,7 +2584,10 @@ async fn large_response(transport1: Transport, transport2: Transport) {
         }
     });
 
-    let response = vec![0; 15 * 1024 * 1024];
+    // Generate the response first and use a fast insecure RNG to make the test not timeout on
+    // GitHub CI when generating 15 MB of data.
+    let mut rng = XorShiftRng::from_rng(rand::thread_rng()).expect("`thread_rng` to seed");
+    let response = (0..15 * 1024 * 1024).map(|_| rng.gen::<u8>()).collect::<Vec<_>>();
 
     let request_id =
         handle1.try_send_request(peer2, vec![1, 3, 3, 7], DialOptions::Reject).unwrap();