Cancel previous run-all-steps #240

	# Syntax reference:
	# https://help.github.com/en/actions/automating-your-workflow-with-github-actions/workflow-syntax-for-github-actions
	#
	# Since the run_all_steps workflow is relatively expensive, only allow one
	# instance to run at once per branch, canceling obsolete runs.
	#
	# Based on https://github.com/styfle/cancel-workflow-action#advanced-pull-requests-from-forks
	#
	# TODO: should we replace this with 'cancel-in-progress'?
	# https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/control-the-concurrency-of-workflows-and-jobs
	name: Cancel previous run-all-steps
	permissions: read-all
	on:
	workflow_run:
	workflows: ["Run all steps"]
	types:
	- requested
	jobs:
	cancel:
	runs-on: ubuntu-latest
	permissions:
	actions: write
	steps:
	# Pin to the current sha of tag 0.9.1. Being a bit extra careful here
	# since this job gets elevated permission.
	- uses: styfle/cancel-workflow-action@a40b8845c0683271d9f53dfcb887a7e181d3918b
	with:
	workflow_id: ${{ github.event.workflow.id }}

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