Use high DPI icons in wxInfoBarGeneric if appropriate

Just switch to using wxArtProvider::GetBitmapBundle() instead of
GetBitmap() which returned standard-sized bitmap that was upscaled
later.

See #18822.

src/generic/infobar.cpp

@@ -224,7 +224,7 @@ void wxInfoBarGeneric::ShowMessage(const wxString& msg, int flags)
     }
     else // do show an icon
     {
-        m_icon->SetBitmap(wxArtProvider::GetBitmap(
+        m_icon->SetBitmap(wxArtProvider::GetBitmapBundle(
                             wxArtProvider::GetMessageBoxIconId(flags),
                           wxART_BUTTON));
         m_icon->Show();