WooCommerce EU VAT Number 2.9.15

* Fix - Improve performance of syncing check for HPOS compatibility mode.
* Dev - Bump WooCommerce "tested up to" version 9.8.
* Dev - Bump WooCommerce minimum supported version to 9.6.
* Dev - Use the `@woocommerce/e2e-utils-playwright` NPM package for E2E tests.
* Dev - Disabled warning checks from WordPress Plugin Check Action.
* Dev - Update all third-party actions our workflows rely on to use versions based on specific commit hashes.

* Fix - VAT application and exemption logic for domestic transactions for shortcode checkout.
* Fix - Add support for Belgian VAT numbers that begin with `1`.
* Dev - Bump WooCommerce "tested up to" version 9.7.
* Dev - Bump WooCommerce minimum supported version to 9.5.
* Dev - Bump WordPress minimum supported version to 6.6.
* Dev - Add the WordPress Plugin Check GitHub Action.

* Fix - Resolved PHP notice caused by loading localization code too early on WordPress 6.7.0+.
* Dev - Bump WooCommerce "tested up to" version 9.6.
* Dev - Bump WooCommerce minimum supported version to 9.4.