This is allowed for existing instances so we don't end up 76 offenses
right away, but for new code one should _only_ use this if they _have_
to remove non database data. Even then it's usually better to do this in
a service class as this gives you more control over how to remove the
data (e.g. in bulk).

updating builds and updating pipelines. We check against
being able to merge or push if the ref is protected.

When sending the usage data, it now includes all pipelines. This commit
will split the pipelines in two; internal and external.

This will lead to historical data being incorrectly marked this way.

Fixes gitlab-org/gitlab-ce#33172

So that we could use it for the schedule before
trying to use CreatePipelineService

And add some specs.

Turn ExpirePipelineCacheService into Worker so it can fetch all the
merge requests for which the pipeline runs or did run against.

Enable caching in the Etag::Middleware and when a pipeline changes
status, expire the cache for the project pipelines path.