Fix triumph.rb: Remove DDP Player.app artifact (#21413)

Triumph.app contains in its bundle three helper tools. Those tools are meant to be accessed from the menu bar while using Triumph.

One of those tools, DDP Player.app, is defined as an artifact though. With upcoming PR #13966, `cask install` would rip out DDP Player.app from the bundle. As a consequence, invoking the *DDP Player* menu item would cause Triumph to crash.

This commit fixes the issue by removing the artifact altogether. All the tools (including DDP Player) should be launched from the *Tools* menu as intended, e. g.:

> Triumph » Tools » DDP Player

Casks/triumph.rb

@@ -8,5 +8,4 @@
   license :commercial
 
   app 'Triumph.app'
-  app 'Triumph.app/Contents/Applications/DDP Player.app'
 end