docs: mark agent metadata as GA (#8111)

* docs: agent metadata is now GA

* fmt

docs/manifest.json

@@ -156,8 +156,7 @@
           "title": "Agent Metadata",
           "description": "Learn how to expose live agent information to users",
           "path": "./templates/agent-metadata.md",
-          "icon_path": "./images/icons/table-rows.svg",
-          "state": "alpha"
+          "icon_path": "./images/icons/table-rows.svg"
         },
         {
           "title": "Parameters",

docs/templates/agent-metadata.md

@@ -1,8 +1,4 @@
-# Agent Metadata (alpha)
-
-<blockquote class="warning">
-Agent metadata is in an alpha state and may break or disappear at any time.
-</blockquote>
+# Agent Metadata
 
 ![agent-metadata](../images/agent-metadata.png)