Add zenity package #21676

	name: Check for bad links in documentation

	on:
	pull_request:
	paths:
	# Only run on changes to .md files -- this check is too flakey to run on every PR
	- '**.md'
	workflow_dispatch: # Manual
	schedule:
	- cron: '0 6 * * *' # Nightly 6AM UTC

	# This allows a subsequently queued workflow run to interrupt previous runs
	concurrency:
	group: ${{ github.workflow }}-${{ github.head_ref \|\| github.run_id}}
	cancel-in-progress: true

	defaults:
	run:
	# fail-fast using bash -eo pipefail. See https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#exit-codes-and-error-action-preference
	shell: bash

	permissions:
	contents: read

	jobs:
	markdown-link-check:
	permissions:
	contents: read # to read files to check dead links
	runs-on: ubuntu-latest
	steps:
	- name: Harden Runner
	uses: step-security/harden-runner@63c24ba6bd7ba022e95695ff85de572c04a18142 # v2.7.0
	with:
	egress-policy: audit

	- uses: actions/checkout@c85c95e3d7251135ab7dc9ce3241c5835cc595a9 # v3.5.3
	- uses: gaurav-nelson/github-action-markdown-link-check@d53a906aa6b22b8979d33bc86170567e619495ec # v1.0.15
	with:
	use-quiet-mode: 'yes'
	config-file: .github/workflows/config/markdown-link-check-config.json
	base-branch: ${{ github.base_ref }}

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