Woo installer: remove unused code

[allilevine]

Details

We've added a new WooCommerce install flow so we can remove most of /my-sites/woocommerce (except the new landing page, WoopLandingPage).

Checklist

• Check with Matt Sherman about removing required-plugins-install-view.jsx.
• Test that the new flow starting at /woocommerce-installation/< site id > still works and doesn't throw errors.
• Follow up: move the landing page out of /my-sites/woocommerce.

[lsl]

Check with Matt Sherman about removing required-plugins-install-view.jsx.

@mattsherman just in case, but this should be fine, the code is leftover from the old store on wpcom feature, its not in use and now that we've re-implemented the functionality under /start it can be deleted.

[allilevine]

Closed by #60784