Update GH actions

[Aariq]

Description

I'm noticing some deprecation warnings in the GitHub actions, so trying to update them.

Node.js 12 actions are deprecated for:

• [x] actions/stale@v4
• [x] infotroph/tree-is-clean@v1
• [x] actions/checkout@v2
• [x] actions/upload-artifact@v2

Other:

• [x] unexpected inputs for elgohr/Publish-Docker-Github-Action@2.18
• [x] set-output command is deprecated (???)

Motivation and Context

Review Time Estimate

• [ ] Immediately
• [ ] Within one week
• [ ] When possible

Types of changes

• [ ] Bug fix (non-breaking change which fixes an issue)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [ ] My change requires a change to the documentation.
• [x] My name is in the list of CITATION.cff
• [ ] I have updated the CHANGELOG.md.
• [ ] I have updated the documentation accordingly.
• [x] I have read the CONTRIBUTING document.
• [ ] I have added tests to cover my changes.
• [ ] All new and existing tests passed.

[infotroph]

Thanks -- these all look right at a glance.

I'll try to find some time to update tree-is-clean over the coming weekend... please prod me again if I left it drop.

[infotroph]

@Aariq Where can I look to see these warnings? I'm not finding them in the logs from recent Actions runs, but maybe I'm looking in the wrong places / not expanding the right sections.

[Aariq]

They're in the "summary" view: https://github.com/PecanProject/pecan/actions/runs/3878905778

Not seeing any warnings on the actions for this PR, so I think it's ready to merge.