Fix `XcursorImageDestroy` interop signature (#14843)

* Fix `XcursorImageDestroy` interop signature

The C API return type is `void`, per https://www.x.org/releases/current/doc/man/man3/Xcursor.3.xhtml#heading6

```c
void XcursorImageDestroy (XcursorImage *image)
```

Update the C# interop method to match.

May help with  https://github.com/AvaloniaUI/Avalonia/issues/10425

* Use `XFreeCursor` instead of `XcursorImageDestroy`

Ref. https://github.com/AvaloniaUI/Avalonia/issues/10425#issuecomment-1981363971

src/Avalonia.X11/X11CursorFactory.cs

@@ -92,6 +92,7 @@ namespace Avalonia.X11
 
         private unsafe class XImageCursor : CursorImpl, IFramebufferPlatformSurface, IPlatformHandle
         {
+            private readonly IntPtr _display;
             private readonly PixelSize _pixelSize;
             private readonly UnmanagedBlob _blob;
 
@@ -101,6 +102,7 @@ namespace Avalonia.X11
                     (bitmap.PixelSize.Width * bitmap.PixelSize.Height * 4);
                 var platformRenderInterface = AvaloniaLocator.Current.GetRequiredService<IPlatformRenderInterface>();
 
+                _display = display;
                 _pixelSize = bitmap.PixelSize;
                 _blob = new UnmanagedBlob(size);
                 
@@ -128,7 +130,7 @@ namespace Avalonia.X11
 
             public override void Dispose()
             {
-                XLib.XcursorImageDestroy(Handle);
+                XLib.XFreeCursor(_display, Handle);
                 _blob.Dispose();
             }
 

src/Avalonia.X11/XLib.cs

@@ -603,9 +603,6 @@ namespace Avalonia.X11
         [DllImport(libXCursor)]
         public static extern IntPtr XcursorImageLoadCursor(IntPtr display, IntPtr image);
 
-        [DllImport(libXCursor)]
-        public static extern IntPtr XcursorImageDestroy(IntPtr image);
-
         public static void XISetMask(ref int mask, XiEventType ev)
         {
             mask |= (1 << (int)ev);