.gitlab-ci.yml: disable REUSE and DCO check

With the move to booting.oniroproject.org, the two compliance jobs now
refer to non-existent repository. They will be re-enabled soon, after
all containers and shared jobs definitions are merged into the oniro
project.

Signed-off-by: Zygmunt Krynicki <zygmunt.krynicki@huawei.com>