allow closure on excludes

[zsp03]

This pull request allows Closure to be used on excludes, this is useful to enable custom logic for excluding panels. For example you can hide "admin" panel from switch if the user is not admin.

PanelSwitch::configureUsing(function (PanelSwitch $panelSwitch) {
    $panelSwitch->excludes(function (): array {
                    if (auth()->user()->role !== 'admin')
                        return ['admin'];
                    return [];
                })
        ]);
    });

[bezhanSalleh]

Thanks.