WooCommerce Product Bundles 8.1.2

* Fix - Declared support for WooCommerce 4.1.
* Tweak - Ensure that the sw-select script is registered before checking its version.
* Tweak - Added tweaks for NYP 3.0 compatibility.

* Tweak - Updated 'Discount' option tooltips.
* Fix - Reverted change introduced in version 6.0.0: When 'Item Grouping > None' is selected for a composited Bundle, customers should be able to add the Composite to the cart without choosing any bundled items. To require customers to choose at least one item, use the free 'Product Bundles - Min/Max Items' add-on.

* Fix - Assembled Composites that contain Product Bundles are now represented correctly in shipping package contents.
* Tweak - Added 'WC_PB()->plugin_initialized()' method.