docs(react-native): Promote Metrics to GA (#17530)

## DESCRIBE YOUR PR
Preparing for Metrics GA

Co-authored-by: Claude <noreply@anthropic.com>

Author: 2 people

docs/platforms/react-native/metrics/index.mdx

@@ -4,13 +4,10 @@ sidebar_title: Metrics
 description: "Metrics allow you to send, view and query counters, gauges and measurements from your Sentry-configured apps to track application health and drill down into related traces, logs, and errors."
 sidebar_order: 6
 sidebar_section: features
-beta: true
 ---
 
 With Sentry's [Application Metrics](/product/explore/metrics/), you can send counters, gauges, and distributions from your applications to Sentry. Once in Sentry, these metrics can be viewed alongside relevant errors, and searched using their individual attributes.
 
-<Alert>This feature is currently in open beta.</Alert>
-
 ## Requirements
 
 <PlatformContent includePath="metrics/requirements" />