This reverts commit 714082e65304ae2ec5c5400c59a68ab63e724aa9.

Two things at ones, as there was no clean way to seperate the commit and
give me feedback from the tests.

But the model Artifact is now JobArtifact, and the table does not have a
type anymore, but the metadata is now its own model:
Ci::JobArtifactMetadata.

To allow jobs/builds to have multiple artifacts, and to start seperating
concerns from Ci::Build a new model is created: Ci::Artifact.

Changes include the updating of the ArtifactUploader to adapt to a
slightly different interface. The uploader expects to be initialized
with a `Ci::Build`.

Futher a migration with the minimal fields, the needed foreign keys and
an index.

Last, the way this works is by prepending a module to Ci::Build so we
can basically override behaviour but if needed use `super` to get the
original behaviour.

Documentation bug fixes: Added procedure to disable built-in Issues.

See merge request gitlab-org/gitlab-ce!15581

Merge branch '40746-broken-master-due-to-failure-in-spec-services-clusters-applications-schedule_installation_service_spec-rb' into 'master'

Ensure `Namespace`'s is namespaced in `Gitlab::Kubernetes::Helm#initialize` and fix a transient failing spec due to that

Closes #40746

See merge request gitlab-org/gitlab-ce!15684

Ensure `Namespace`'s is namespaced in `Gitlab::Kubernetes::Helm#initialize` and fix a transient failing spec due to that
Signed-off-by: Rémy Coutable <remy@rymai.me>

Show only group name by default and put full namespace in tooltip in Groups tree

Closes #40286

See merge request gitlab-org/gitlab-ce!15650

Extract class responsible for building a pipeline

Closes #38460

See merge request gitlab-org/gitlab-ce!14762

Adds validation for Project#ci_config_path not to contain leading slash

Closes #34683

See merge request gitlab-org/gitlab-ce!15672