[faucet] Do not log 429 errors (#20930)

## Description 

This PR updates the logging of 429 errors, to skip them as it floods the
logs with them after rate limiting the server.

## Test plan 

How did you test the new or updated feature?

---

## Release notes

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that describes the impact of your changes that a user might notice and
any actions they must take to implement updates.

- [ ] Protocol: 
- [ ] Nodes (Validators and Full nodes): 
- [ ] gRPC:
- [ ] JSON-RPC: 
- [ ] GraphQL: 
- [ ] CLI: 
- [ ] Rust SDK:

Author: stefan-mysten

crates/sui-faucet/src/metrics_layer.rs

@@ -175,10 +175,13 @@ impl MetricsGuard {
                     self.path, elapsed, err
                 );
             } else if let Some(status) = status {
-                error!(
-                    "Request failed for path {} in {:.2}s with status: {}",
-                    self.path, elapsed, status
-                );
+                // don't log too many requests as an error, as we're flooding the logs
+                if status != StatusCode::TOO_MANY_REQUESTS {
+                    error!(
+                        "Request failed for path {} in {:.2}s with status: {}",
+                        self.path, elapsed, status
+                    );
+                }
             } else {
                 warn!("Request failed for path {} in {:.2}s", self.path, elapsed);
             }