WooCommerce Advanced Notifications 1.6.6

* Tweak - WooCommerce 10.0 Compatibility.

* Tweak - WooCommerce 9.9 Compatibility.

* Update Requires headers for WooCommerce compatibility.
* Update to ubuntu-latest to fix QIT tests.

* Tweak - PHP 8.4 Compatibility.

* Tweak - WordPress 6.7 Compatibility.

* Fix - Apply WordPress coding standards.

Fix - Plain text email formatting.

Security update.

Add - Dev dependencies to run coding standards.

* Fix - Incorrect email class for new order email.