Update AZ400_M03_L07_Configure_Pipelines_as_Code_with_YAML.md to use task DownloadBuildArtifacts@1

[rob-foulkrod]

Related Issue

Link related Github Issue 🢂 Fixes #583

Checklist

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• [x] Has related GitHub Issue 💥 Create Issue 📝
• [x] Tested it
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Changes proposed in this pull request:

• Change the task: DownloadBuildArtifacts@0 to task: DownloadBuildArtifacts@1 to allow pipeline to run successfully