Keyboard lag during precompiling of packages that use Gtk4 on Windows

[jwahlstrand]

On Windows, when GtkObservables and ImageView are being precompiled I notice a debilitating amount of keyboard lag on all other software (specifically noticed in browsers, MS Word, and Outlook). It only lasts a minute or so but is very annoying. I think this issue probably occurs for any package that calls Gtk4 functions during precompiling via PrecompileTools.