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 #35568

• This PR is a very minor change/addition and does not require testing instructions (if checked you can ignore/remove the next section).

How to test the changes in this Pull Request:

1. Go to Products -> Add New (MVP) page
2. Under Attributes section click on Add first attribute button
3. The Add attributes modal should be shown.
4. By default if you don't select any attribute under the attribute search field then the attribute value field should be disabled and with 50% of opacity.
5. After selecting an attribute from the search field the value field should become enable and with it's normal colors.

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 created a changelog file for each project being changed, ie pnpm --filter=<project> changelog add?

FOR PR REVIEWER ONLY:

• I have reviewed that everything is sanitized/escaped appropriately for any SQL or XSS injection possibilities. I made sure Linting is not ignored or disabled.