apertis-pkg-merge-upstream-to-downstreams: ensure merge request is created against the right project

In case of a forked project, like we are doing with the test of the rebase,
the GitLab API creates by default the MR against the original project
instead of the forked project.
To ensure the merge request is created against the forked project, we use
the push option merge_request.target_project to overwrite the default
behavior and to create the merge request against the forked project.

See:
https://docs.gitlab.com/ee/topics/git/commit.html#push-options-for-merge-requests



Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>

apertis-pkg-merge-upstream-to-downstreams: Don't print useless information while canceling pipelines

Printing these values only creates noise in the log.

Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>

Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>

Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>

Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>

apertis-pkg-merge-upstream-to-downstreams: cancel pipelines created through the creation of a branch

Due to GitLab limitation (https://gitlab.com/gitlab-org/gitlab/-/issues/26422

),
it's currently impossible to avoid to trigger a pipeline when creating a
branch with the API. Since these useless pipelines are wasting
GitLab and OBS ressources (and devs' time), as a workaround for now
we can cancel them.

Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>

apertis-pkg-merge-upstream-to-downstreams: Add link to the bug report about missing skip_ci option in REST API

Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>

Only the pipeline in merge request context is relevant here.
"ci.skip" only affect branch pipelines and not merge request pipelines.
See https://docs.gitlab.com/ee/gitlab-basics/add-file.html#push-options-for-gitlab-cicd



Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>

These tools come from:
https://gitlab.apertis.org/infrastructure/apertis-docker-images/-/tree/apertis/v2025dev3



Signed-off-by: Dylan Aïssi <dylan.aissi@collabora.com>