Add 0.75 announcement (#727)

announcements.json

@@ -1,8 +1,8 @@
 [
   {
-    "tag": "Preview",
-    "text": "The new NetBird desktop app is here - now available as a 0.75 release candidate.",
-    "link": "https://github.com/netbirdio/netbird/discussions/6483",
+    "tag": "New",
+    "text": "The new NetBird desktop app is here - now available in the v0.75 release.",
+    "link": "https://netbird.io/knowledge-hub/netbird-v0-75-new-desktop-app",
     "linkText": "Learn more",
     "variant": "important",
     "isExternal": true,

src/utils/netbird.ts

@@ -104,13 +104,10 @@ export const isAgentNetworkOnly = () => {
 };
 
 // pkgsDownloadUrl builds a NetBird client installer download link on
-// pkgs.netbird.io. In Agent Network-only mode the client ships from the
-// release-candidate channel, so the link gets a "/rc" suffix that
-// pkgs.netbird.io 302-redirects to the latest RC GitHub asset (e.g.
-// "windows/x64" -> "windows/x64/rc"). `path` is the platform path without a
+// pkgs.netbird.io. `path` is the platform path without a
 // leading slash, e.g. "windows/x64" or "macos/universal".
 export const pkgsDownloadUrl = (path: string) =>
-  `https://pkgs.netbird.io/${path}${isAgentNetworkOnly() ? "/rc" : ""}`;
+  `https://pkgs.netbird.io/${path}`;
 
 // isAgentNetworkEnabled returns true when the Agent Network product surface
 // (Providers, Policies, Usage & Logs) is available — in either the dedicated