Remove 3.1.13 update step from lifecycle

[layoutd]

Changes proposed in this Pull Request:

As reported in the forums: https://wordpress.org/support/topic/php-fatal-error-uncaught-error-class-woocommerce/

If a merchant has Facebook for WooCommerce < 3.1.13 and Messenger enabled, and then updates directly to ≥ 3.2.0, an error is triggered during the update lifecycle process due to a class that was removed in 3.2.0 being referenced in the update step for 3.1.13.

This PR removes the 3.1.13 update step altogether, as it just added an notice warning about the upcoming May 2024 deprecation of the Facebook Messenger chat plugin. Since we're now past that date, there's no reason to even consider it. It is mentioned in the 3.2.0 update method, however, since it's possible that users that update < 3.1.13 → 3.1.13-3.1.15 will have the deprecation notice, so updating again to ≥ 3.2.0 should still remove it.

Detailed test instructions:

To reproduce:

1. Install and activate v3.2.0.
2. In include/Lifecycle.php, set $is_messenger_enabled = true; to force the condition.
3. Downgrade the version in facebook-for-woocommerce.php to 3.1.11 in the docs and the version constant:

# Line 14
 * Version: 3.1.11
# Line 48
	const PLUGIN_VERSION = '3.1.11'; // WRCS: DEFINED_VERSION.

4. Update the FB version DB options:

UPDATE `wp_options` SET `option_value` = '3.1.11' WHERE `option_name` = 'wc_facebook_for_woocommerce_version';
UPDATE `wp_options` SET `option_value` = '[]' WHERE `option_name` = 'wc_facebook_for_woocommerce_lifecycle_events';

SELECT * FROM `wp_options` WHERE option_name IN ('wc_facebook_for_woocommerce_version', 'wc_facebook_for_woocommerce_lifecycle_events');

5. Confirm the version is 3.1.11:
   
6. Revert the values from step 3 to 3.2.0
7. Confirm the error in WP Admin:

Fatal error: Uncaught Error: Class "WooCommerce\Facebook\Admin\Settings_Screens\Messenger" not found in /var/www/html/wp-content/plugins/facebook-for-woocommerce/includes/Lifecycle.php:321

To confirm fix:

1. Checkout this PR branch.
2. Repeat steps 3 - 6 above. (Note that step 2 isn't necessary as the code is no longer present).
3. Confirm version is updated to 3.2.0 correctly.

Changelog entry

Fix - Direct upgrade path from < 3.1.13 to ≥ 3.2.0.

[budzanowski]

Looks good. Will fix the error.