winrt: Removed WinRT/Windows Phone/UWP support.

Fixes #10724.

build-scripts/SDL_migration.cocci

@@ -3117,11 +3117,6 @@ typedef SDL_Colour, SDL_Color;
 + SDL_Color
 @@
 @@
-- SDL_WinRTGetFSPathUTF8
-+ SDL_GetWinRTFSPath
-  (...)
-@@
-@@
 - SDL_iPhoneSetAnimationCallback
 + SDL_SetiOSAnimationCallback
   (...)
@@ -3527,11 +3522,6 @@ typedef SDL_Colour, SDL_Color;
   (...)
 @@
 @@
-- SDL_WinRTGetDeviceFamily
-+ SDL_GetWinRTDeviceFamily
-  (...)
-@@
-@@
 - SDL_LinuxSetThreadPriority
 + SDL_SetLinuxThreadPriority
   (...)