remove non-support for custom ports (#7089)

Author: afgiel

docs/activities/Development_Guides.mdx

@@ -657,16 +657,10 @@ export default function LayoutMode() {
 
 ### Activity Proxy Considerations
 
-All network traffic is routed through the Discord Proxy for various security reasons. The proxy does not support mapping targets to specific ports. Any mapping to specific ports will have to be handled by your application.
+All network traffic is routed through the Discord Proxy for various security reasons.
 
 Under the hood we utilize Cloudflare Workers, which brings some restrictions, outlined below.
 
-#### iframe Supported Ports
-When an activity's iframe makes a request (i.e. to https://<app_id>.discordsays.com), url port usage is limited to Cloudflare's list of supported ports as shown [here](https://developers.cloudflare.com/fundamentals/reference/network-ports/#network-ports-compatible-with-cloudflares-proxy).
-
-#### Url Mapping Target Supported Ports
-At this time, URL mapping targets do not support external url ports. This is a [known issue](https://developers.cloudflare.com/workers/platform/known-issues/#custom-ports) of Cloudflare workers.
-
 #### WebTransport
 
 While we currently only support websockets, we're working with our upstream providers to enable WebTransport.