XT WooCommerce Floating Cart Pro 2.7.9

When deleting all products from the cart, the close button disappears even if the cart is still open.
Minor css fixes

- **fix**: Disable within new Widget Block Editor to avoid conflicts
- **fix**: Fixed intermittent error: Undefined variable: is_bundle_item when updating item quantity
- **fix**: Fixed conflict within the new Block-based Widgets Editor in WordPress 5.8
- **support**: Support native "woocommerce_update_cart_validation" hook to validate item quantity change

- **fix**: Fixed conflict with Stripe For WooCommerce plugin when Express Checkout Form is enabled.
- **fix**: Disable quantity input for bundled items.