Devstack provisioning breaks with new demo course

Description

The demo course was updated in https://github.com/openedx/openedx-demo-course/pull/47 and devstack provisioning no longer works. This includes a new course key (new name and org) and the course content being moved a few directories deeper.

We have a temporary workaround to pin the old version of the demo course (https://github.com/openedx-unsupported/devstack/pull/1274) but should put in a more permanent fix. The PR https://github.com/openedx-unsupported/devstack/pull/1272 should fix this as far as the devstack repo itself is concerned, but there seem to be additional references to the course key outside of the devstack repo that might be causing problems.

An attempt to fix this issue

An old PR https://github.com/openedx-unsupported/devstack/pull/1272 can be used as a reference to fix this issue.

まず、古い devstack の PR #1272 と一時的な workaround の PR #1274 を確認し、その後、devstack リポジトリ外でデモコースのキーへの参照を追跡します。完了条件は、古い固定バージョンを必要とせず、更新された openedx-demo-course で devstack のプロビジョニングが動作することです。