Fix potential startup crash if resolution/display pair from configuration results in no valid resolution

[peppy]

Closes https://github.com/ppy/osu/issues/19877#issuecomment-1221438234.

I wasn't able to reproduce what the user was seeing even when trying my best to break it, but have tested the flow works by artifically adding an exception:

diff --git a/osu.Framework/Platform/SDL2DesktopWindow.cs b/osu.Framework/Platform/SDL2DesktopWindow.cs
index 8ca11367f..d68d8368f 100644
--- a/osu.Framework/Platform/SDL2DesktopWindow.cs
+++ b/osu.Framework/Platform/SDL2DesktopWindow.cs
@@ -1233,6 +1233,9 @@ private void updateWindowStateAndSize()
                     {
                         var closestMode = getClosestDisplayMode(sizeFullscreen.Value, currentDisplayMode.Value.RefreshRate, currentDisplay.Index);
 
+                        if (!sizeFullscreen.IsDefault)
+                            throw new InvalidOperationException("test");
+
                         Size = new Size(closestMode.w, closestMode.h);
 
                         SDL.SDL_SetWindowDisplayMode(SDLWindowHandle, ref closestMode);