Fix offsets not calculated correctly sometimes on select2 dropdowns …

[roykho]

…closes #29163

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:

Closes #29163 #28996

How to test the changes in this Pull Request:

1. Install/activate jQuery Migrate Plugin so you can easily switch the two different jQuery versions for testing.
2. Add an attributes filter widget to your shop. Use Dropdown as display type.
3. Go to the shop page and click on the Select2 dropdown and ensure the dropdown shows correctly aligned and that you can select any of the attributes listed. Select an attribute and let page reload.
4. Click on the dropdown again and ensure it expands correctly and you are able to select other attributes as well.
5. Do the same test with and without the admin toolbar visible. You can change this in your user settings.
6. Also do the same tests (3 to 6) with the dropdown going upwards when not enough room to show on the bottom.
7. Now do the same tests again (3 to 6) with using older jQuery version by changing the settings in jQuery Migrate plugin. Ensure all is looking nice.
8. Also check that the dropdown is showing nicely in checkout page (country selection).

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?

Note

In older legacy jQuery version the dropdown in the country selection has a slight pixel or two off on the right side container. But that was always there so it isn't fixed by this PR.

Changelog entry

• Fix - offsets not calculated correctly sometimes on select2 dropdowns causing usability issues.