ci: Update actions/checkout to v4 from v3.

[waywardmonkeys]

This updates internally to using Node 20 and removes some deprecation notices within the GitHub Actions UI about Node 16 being deprecated.

[rptb1]

Executing proc.review.express:

1. Start time 15:42.
2. Source documents: GitHub Actions; All Actions will run on Node20 instead of Node16 by default, Workflow syntax
3. Applied entry.universal and entry.impl.
4. Called in @thejayps .
5. @thejayps agrees this looks low risk and express review is appropriate.

Checking commences 15:50.

[rptb1]

Executing proc.review.check

1. Start time 15:51.
2. m. It's not entirely clear why we have to say "@v4" except that's what GitHub gives as an example and it works. It seems likely to be stable for a long time though. The README for the checkout project refers to it as "V4". Probably best practice. I skimmed a few best practices and security documents. If want to be really hard about it we might say @<hash>.

[rptb1]

Executing proc.review.express.brainstorm:

1. Regular builds (Changes in the build environment are not caught until there's a change in the MPS #294 ) would help catch this sort of failure sooner. We might have seen the warnings mention on the blog.

[waywardmonkeys]

That indicates which git tag to use, indicating which version should be used. The v4 keeps it on the 4.x version.

[rptb1]

That indicates which git tag to use, indicating which version should be used. The v4 keeps it on the 4.x version.

Yes. I was more wondering why that's how it's done. Not a big deal though.

[rptb1]

proc.review.exit.pass

[rptb1]

Executing proc.merge.pull-request.

1. Start time 16:17.
2. Merge completed 16:20.

[rptb1]

@thejayps asks why my merge was so fast. Well, I already created the merge branch in order to make 8d2019b so I was primed!

[rptb1]

@thejayps asks why my merge was so fast. Well, I already created the merge branch in order to make 8d2019b so I was primed!

Except I fell foul of Git's constant astonishment and caused the merge commit to vanish on master. See #228 (comment) . Always follow written procedure where GIt is concerned.