bugfix: Mark fetch as unsupported on Windows for now

This fetch function has been broken and is probably unsound. This also
fixes the flakey Windows CI that we've been dealing with.

Signed-off-by: John Nunley <dev@notgull.net>

src/win32.rs

@@ -231,30 +231,7 @@ impl Win32Impl {
 
     /// Fetch the buffer from the window.
     pub fn fetch(&mut self) -> Result<Vec<u32>, SoftBufferError> {
-        let buffer = self.buffer.as_ref().unwrap();
-        let temp_buffer = Buffer::new(self.dc, buffer.width, buffer.height);
-
-        // Just go the other way.
-        unsafe {
-            Gdi::BitBlt(
-                temp_buffer.dc,
-                0,
-                0,
-                temp_buffer.width.get(),
-                temp_buffer.height.get(),
-                self.dc,
-                0,
-                0,
-                Gdi::SRCCOPY,
-            );
-        }
-
-        // Flush the operation so that it happens immediately.
-        unsafe {
-            Gdi::GdiFlush();
-        }
-
-        Ok(temp_buffer.pixels().to_vec())
+        Err(SoftBufferError::Unimplemented)
     }
 }