Core: Fix rust benchmark for unmaintained advisory (#5000)

Signed-off-by: James Xin <james.xin@improving.com>

Author: jamesx-improving

benchmarks/rust/Cargo.toml

@@ -18,7 +18,7 @@ itoa = "1.0.6"
 clap = { version = "4.3.8", features = ["derive"] }
 chrono = "0.4.26"
 serde_json = "1.0.99"
-statistical = "1.0.0"
+average = "0.15"
 tikv-jemallocator = "0.5.4"
 
 [profile.release]

benchmarks/rust/src/main.rs

@@ -12,6 +12,7 @@ use futures::{self, StreamExt, future::join_all, stream};
 use glide_core::client::{Client, ConnectionRequest, NodeAddress, TlsMode};
 use rand::{Rng, thread_rng};
 use serde_json::Value;
+use average::{Mean, Variance};
 use std::{
     cmp::max,
     collections::HashMap,
@@ -197,8 +198,12 @@ fn calculate_latencies(values: &[Duration], prefix: &str) -> HashMap<String, Val
     let p50 = latencies[(len * 0.5) as usize];
     let p90 = latencies[(len * 0.9) as usize];
     let p99 = latencies[(len * 0.99) as usize];
-    let avg = statistical::mean(&latencies);
-    let stddev = statistical::standard_deviation(&latencies, None);
+    
+    let mean_calc: Mean = latencies.iter().copied().collect();
+    let avg = mean_calc.mean();
+    
+    let variance_calc: Variance = latencies.iter().copied().collect();
+    let stddev = variance_calc.population_variance().sqrt();
 
     map.insert(format!("{prefix}_p50_latency"), p50.into());
     map.insert(format!("{prefix}_p90_latency"), p90.into());