move client-cert gauges behind an otel feature of swarm-secret-client, drop the crate

swarm-review-classifier/src/cost.rs

@@ -171,7 +171,7 @@ fn build() -> Option<(SdkMeterProvider, Counters)> {
         .build();
     let provider = SdkMeterProvider::builder().with_reader(reader).build();
     let counters = counters(&provider);
-    swarm_cert_metrics::register(
+    swarm_secret_client::cert_metrics::register(
         &provider.meter("hyperhive.review_classifier"),
         "review-classifier",
     );