WP 5.5 doesn't introduce a tag inside metaboxes headings

All Submissions:

• Have you followed the WooCommerce Contributing guideline?
• Does your code follow the WordPress' coding standards?
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Changes proposed in this Pull Request:

There's no "Product type" dropdown using on WordPress 5.5-RC1-48681:

This happens because WP Core changed the heading of meta boxes, before used to be something like <h2><span>Product Data</span></h2>, but on WP 5.5 it changed to <h2>Product Data</h2>

Closes #27167.

How to test the changes in this Pull Request:

1. Install WP 5.5, you can install using WP-CLI: wp core update --version=nightly --force
2. Go to wp-admin/post-new.php?post_type=product
3. Check that there's no "Product type" dropdown or the "Virtual" and "Downlodable" checkboxes.
4. Checkout to this branch and run grunt assets
5. Go back to wp-admin/post-new.php?post_type=product and check if it's all fixed now.

Other information:

• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your changes, as applicable?
• Have you successfully run tests with your changes locally?

Changelog entry

Fix - "Product type" dropdown missing from Product's data meta box on WP 5.5