Describe the bug
WordPress isn't able to complete a loopback request when running under wp-env.

To reproduce

1. npx wp-env start
2. Navigate to http://localhost:8888/wp-admin/site-health.php

There's two errors related to this:

• The REST API encountered an error
• Your site could not complete a loopback request

Expected behavior
There should only be one critical error (the one about debug mode.)

Additional context
WordPress is trying to make a request to http://localhost:8888 from the underlying Docker container but this fails because Apache is listening on port 80. One solution would be to set up the docker-compose.yml config to map localhost to the host machine.