Foreign key for Pipeline schedule owner

Closes #31932

See merge request !11233

Runners tab is now CI/CD Pipelines

See merge request !11326

When the owner of a pipelines schedule was either blocked or was removed
from the project, the pipeline schedular would still schedule the
pipeline.

This would than fail however, given the user had no access to the
project and it contents. However, a better way to handle it would be to
not schedule it at all. Furthermore, from now on, such schedules will be
deactivated so the schedule worker can ignore it on the next runs.

Allow numeric values in gitlab-ci.yml

Closes #30017

See merge request !10607

Fix typo in code snippet to match text below

See merge request !11101

fix $CI_JOB_ID variable

See merge request !10966