homescreens/folio: Wallpaper blur causes extreme lag on the pinephone

While it seems to work fine on SDM845 devices, the wallpaper blur seems to cause extreme lag on the pinephone

https://invent.kde.org/plasma/plasma-mobile/-/blob/90e31aff0639c56cc6afbfe916f7401ee4dce203/containments/homescreens/folio/package/contents/ui/main.qml#L42