Allow to trigger the documentation job without having the release stage completed

Even if the release stage is not complete In case PyPI release job is not trigger on the tag based pipeline https://docs.gitlab.com/ee/ci/yaml/#needs

.gitlab-ci.yml

@@ -143,3 +143,4 @@ pages:
     - if: $CI_COMMIT_BRANCH == "master"
       when: manual
     - when: never
+  needs: []