Add timestamp/SHA to PR comment

[bennibbelink]

Closes issue #1707. Adds a timestamp and commit hash to the PR comment generated on downstream testing

[github-actions]

Downstream Build Status Report

Build FROM cyclus_20.04_apt/cyclus

• Cycamore: Success ✅
• Cymetric: Success ✅

Build FROM cyclus_20.04_conda/cyclus

• Cycamore: Success ✅
• Cymetric: Success ✅

Build FROM cyclus_22.04_apt/cyclus

• Cycamore: Success ✅
• Cymetric: Success ✅

Build FROM cyclus_22.04_conda/cyclus

• Cycamore: Success ✅
• Cymetric: Success ✅

[coveralls]

Pull Request Test Coverage Report for Build 8410579111

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 32.594%

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Totals
Change from base Build 8381657162:	0.0%
Covered Lines:	53047
Relevant Lines:	129057

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💛 - Coveralls

[bennibbelink]

Unfortunately we're not seeing what the comment will look like after this PR is merged. I think it might be because of how pr_comment.yml is triggered (by the completion of build_test.yml). This is what the header of the comment will look like:

Downstream Build Status Report - 10ba101

[gonuke]

I this meant to add a timestamp as well? or just a commit hash?

[bennibbelink]

I initially had it add a timestamp too but figured the commit hash was more relevant. Forgot to change the PR title. I can add the timestamp back in if you'd like me to.

[gonuke]

I think both are useful since it can often be easier to check the timestamp without cross-referencing

[gonuke]

Thanks @bennibbelink - let's give this a shot