fix nightly 1.75 (#5719)

## Problem

Neon doesn't compile on nightly and had numerous clippy complaints.

## Summary of changes

1. Fixed troublesome dependency
2. Fixed or ignored the lints where appropriate

proxy/src/console/provider/mock.rs

@@ -59,7 +59,7 @@ impl Api {
             let rows = client.query(query, &[&creds.user]).await?;
 
             // We can get at most one row, because `rolname` is unique.
-            let row = match rows.get(0) {
+            let row = match rows.first() {
                 Some(row) => row,
                 // This means that the user doesn't exist, so there can be no secret.
                 // However, this is still a *valid* outcome which is very similar

proxy/src/scram.rs

@@ -18,7 +18,6 @@ mod password;
 pub use exchange::Exchange;
 pub use key::ScramKey;
 pub use secret::ServerSecret;
-pub use secret::*;
 
 use hmac::{Hmac, Mac};
 use sha2::{Digest, Sha256};