Fix e2e tests

[jorgemd24]

Changes proposed in this Pull Request:

Closes # .

E2E tests are failing due to the fact that the shop page and product items are blockified when utilizing the twenty twenty three template. See here: https://github.com/woocommerce/google-listings-and-ads/actions/runs/5794717342/job/15705036856?pr=2049

For instance, when using the twenty twenty three template, the "add to cart" option appears as a button:

<button href="?add-to-cart=34" class="wp-block-button__link wp-element-button wc-block-components-product-button__button add_to_cart_button ajax_add_to_cart product_type_simple has-font-size has-small-font-size has-text-align-center added" style="margin-bottom:1rem;" data-product_id="34" data-product_sku="" aria-label="Add “Simple product” to your cart" rel="nofollow">Add to cart</button><a href="http://localhost:8889/cart/" class="added_to_cart wc-forward" title="View cart">View cart</a>

In contrast, when it is not blockified is rendered as a link:

<a href="?add-to-cart=12" data-quantity="1" class="button product_type_simple add_to_cart_button ajax_add_to_cart" data-product_id="12" data-product_sku="" aria-label="Add “Simple product” to your cart" aria-describedby="" rel="nofollow">Add to cart</a>

And the shopper utility from the e2e utils package is expecting a link: https://github.com/woocommerce/woocommerce/blob/trunk/packages/js/e2e-utils/src/flows/shopper.js#L45C23-L45C23

As a result, causing the tests to not pass.

This PR sets the theme to twentytwentyone which does not use blocks.

Screenshots:

Detailed test instructions:

1. Check that e2e tests are OK.

Additional details:

• In our new tests with PlayWright we should consider the case when the template uses blocks.

Changelog entry

Dev - Fix E2E tests

[puntope]

✅ Thanks for the fix, I see the tests passing now