Navigation-related code is causing deprecation warnings in debug log

[mattsherman]

Describe the bug

The Navigation feature has been removed from WooCommerce and the related code will be removed in the future. Currently, deprecation warnings are being logged whenever an admin page is rendered:

Automattic\WooCommerce\Admin\Features\Navigation\Menu::add_plugin_item is deprecated since 9.3 with no alternative. Navigation classes will be removed in WooCommerce 9.4
Automattic\WooCommerce\Admin\Features\Navigation\Screen::register_post_type is deprecated since 9.3 with no alternative. Navigation classes will be removed in WooCommerce 9.4

This is due to the following code:

https://github.com/Automattic/woocommerce-subscriptions-core/blob/36e21730f5f322c4fed3f17707334be72dfd552d/includes/admin/class-wcs-wc-admin-manager.php#L74-L96

To Reproduce

1. Activate WooCommerce Subscriptions
2. Load an admin page
3. Note that deprecation messages are in debug log

Expected behavior

Navigation-related code will be removed and no deprecation warnings will be logged.

Actual behavior

Deprecation warnings are logged.

Product impact

• [ ] Does this issue affect WooCommerce Subscriptions? yes/no/tbc, add issue ref
• [ ] Does this issue affect WooCommerce Payments? yes/no/tbc, add issue ref

Additional context

[chrism245]

8729143-zen

[nicdwilson]

8731994-zd-a8c

[shrutimoorthy]

8732890-zen