Change pipeline:expedite to be a pipeline::expedited scoped label

Proposal

The idea is to have pipeline::expedited and the pipeline::tier-* labels mutually exclusive, so that our pre-merge checks in the merge train don't check the tier when the pipeline name include types:expedited.

Tasks

• Update the triage-ops PipelineTierLabel processor to not add a pipeline::tier-* label when pipeline::expedite is set: gitlab-org/quality/triage-ops!2845 (merged)
• Update the set-pipeline-name job to add expedited to the types include expedited: gitlab-org/gitlab!155104 (merged)
• Update the label from pipeline:expedite to pipeline::expedite