fix(site): remove erroneous "install Cursor" notification for Cursor Desktop (#20875)

### Summary

This change removes the erroneous “Install Cursor” notification in the
desktop environment when Cursor is already installed. The issue is the
timeout of 500ms was simply too short for Cursor Desktop to respond in
time, so I increased it to 1500ms. This seems to consistently work, but
it could easily be increased to 2000ms to be safe.

### Issue

Fixes #20289

### Testing

- Verified that when Cursor is installed, the notification no longer
appears

### QA

#### Before


https://github.com/user-attachments/assets/facd2e74-6eb7-47ac-935d-7b11974648a0

#### After


https://github.com/user-attachments/assets/ced817d8-ca0c-428c-8436-5f30ffc6134b

site/src/modules/apps/useAppLink.ts

@@ -55,7 +55,7 @@ export const useAppLink = (
 			// When browser recognizes the protocol and is able to navigate to the app,
 			// it will blur away, and will stop the timer. Otherwise,
 			// an error message will be displayed.
-			const openAppExternallyFailedTimeout = 500;
+			const openAppExternallyFailedTimeout = 1500;
 			const openAppExternallyFailed = setTimeout(() => {
 				// Check if this is a JetBrains IDE app
 				// starts with "jetbrains-gateway://connect#type=coder" (from https://registry.coder.com/modules/coder/jetbrains-gateway)