cmake: Don't add Idian playground when feature is disabled

frontend/cmake/feature-idian-playground.cmake

@@ -6,4 +6,6 @@ if(ENABLE_WIDGET_PLAYGROUND)
     PRIVATE forms/OBSIdianPlayground.ui dialogs/OBSIdianPlayground.hpp dialogs/OBSIdianPlayground.cpp
   )
   target_enable_feature(obs-studio "Widget Playground" ENABLE_WIDGET_PLAYGROUND)
+else()
+  target_disable_feature(obs-studio "Widget Playground")
 endif()

frontend/cmake/ui-dialogs.cmake

@@ -37,6 +37,4 @@ target_sources(
     dialogs/OBSRemux.hpp
     dialogs/OBSWhatsNew.cpp
     dialogs/OBSWhatsNew.hpp
-    dialogs/OBSIdianPlayground.cpp
-    dialogs/OBSIdianPlayground.hpp
 )