ci: Provide basic `.pipeline/config.yaml`
ci: Provide basic `.pipeline/config.yaml`

Migrate away from deprecated service-pipeline-test and
service-pipeline-test-and-publish jobs in favor of bespoke PipelineLib
based pipelines.

See https://wikitech.wikimedia.org/wiki/PipelineLib/Guides/How_to_configure_CI_for_your_project

Bug: T307507
Change-Id: I58007b52335bee9fc439cf1b5b186d75527ec0d2

wikimedia/change-propagation,wikimedia/change-propagation