Remove 'Whitehall' dependency from Smart Answers

Smart Answers makes requests to `/api/content/world`, which
used to be a Whitehall API.

This is no longer the case: alphagov/whitehall#7941

projects/smart-answers/docker-compose.yml

@@ -27,7 +27,6 @@ services:
       - publishing-api-app
       - static-app
       - content-store-app
-      - whitehall-app
     environment:
       GOVUK_PROXY_STATIC_ENABLED: "true"
       VIRTUAL_HOST: smart-answers.dev.gov.uk
@@ -43,7 +42,6 @@ services:
       - publishing-api-app
       - static-app
       - content-store-app
-      - whitehall-app
     environment:
       GOVUK_PROXY_STATIC_ENABLED: "true"
       VIRTUAL_HOST: smart-answers.dev.gov.uk