orbstack: Switch from beta to stable redirect URL

Since September 2023, OrbStack has had separate Stable and Canary update channels. The beta URL is kept for compatibility purposes but should no longer be used.

Casks/o/orbstack.rb

@@ -11,7 +11,7 @@ cask "orbstack" do
   homepage "https://orbstack.dev/"
 
   livecheck do
-    url "https://orbstack.dev/download/beta/latest/#{arch}"
+    url "https://orbstack.dev/download/stable/latest/#{arch}"
     regex(/OrbStack[._-]v?(\d+(?:[._-]\d+)+)[._-]#{arch}\.dmg/i)
     strategy :header_match
   end