Replace 'metric_bucket' with 'trace_metric' in docs (#15398)

Author: cleptric

develop-docs/sdk/expected-features/rate-limiting.mdx

@@ -97,7 +97,7 @@ While these [data categories](https://github.com/getsentry/relay/blob/master/rel
   - `profile_chunk`: Continuous Profiling chunks
   - `replay`: Session Replays
   - `feedback`: User Feedbacks
-  - `metric_bucket`: Sentry Metrics sent via the `statsd` or `metrics` items. The `namespaces` component of the *quota_limit* defines which namespace(s) will be affected.
+  - `trace_metric`: Metric type events
   - `internal`: a sentry/system internal event[^internal]
 
 - **Scope**: The unit / model in Sentry that quotas are enforced for.