Try 'latest' github actions

[JeffFessler]

This is a test to see if @latest works uniformly.

[coveralls]

Pull Request Test Coverage Report for Build 3308145799

Warning: This coverage report may be inaccurate.

This pull request's base commit is no longer the HEAD commit of its target branch. This means it includes changes from outside the original pull request, including, potentially, unrelated coverage changes.

• For more information on this, see Tracking coverage changes with pull request builds.
• To avoid this issue with future PRs, see these Recommended CI Configurations.
• For a quick fix, rebase this PR at GitHub. Your next report should be accurate.

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 80.374%

---

Totals
Change from base Build 3308086344:	0.0%
Covered Lines:	172
Relevant Lines:	214

---

💛 - Coveralls

[codecov]

Codecov Report

Base: 80.37% // Head: 80.37% // No change to project coverage 👍

Coverage data is based on head (a9c3640) compared to base (d620db0).
Patch has no changes to coverable lines.

❗ Current head a9c3640 differs from pull request most recent head fe672e9. Consider uploading reports for the commit fe672e9 to get more accurate results

Additional details and impacted files

@@           Coverage Diff           @@
##           master      #62   +/-   ##
=======================================
  Coverage   80.37%   80.37%           
=======================================
  Files           8        8           
  Lines         214      214           
=======================================
  Hits          172      172           
  Misses         42       42           

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[JeffFessler]

Well, actions/cache@latest failed the Documentation run, so undoing that change.

[JeffFessler]

Sadly checkout@latest did not work either (failed Documentation run) so reverting to @v3 there.

Summary is that @latest seems to work with setup-julia and ubuntu-latest but not with github's own actions like checkout and cache so sadly it seems we must keep the specific v3 in there and someone will have to update that again some day if/when github requires it.