MNT: upgrade upload/download-artifact GitHub actions

[neutrinoceros]

Description

Hi, version 4 of upload-artifact and download-artifact were recently released.
Staying on old version is not viable long term because GitHub will sooner or later drop support for the old versions of node that these depend on.
Since migration to v4 is not as straightfoward as bumping the version number, I'm helping all astropy-related packages byt manually performing the necessary changes.

[github-actions]

Thank you for your contribution! 🌌 This checklist is meant to remind the package maintainers who will review this pull request of some common things to look for.

• Do the proposed changes actually accomplish desired goals?
• Do the proposed changes follow the STScI coding guidelines?
• Are tests added/updated as required? If so, do they follow the STScI testing guidelines?
• Are docs added/updated as required?
• Is rebase and/or squash necessary? If so, please provide the author with appropriate instructions.
• Did the CI pass? If no, are the failures related?
• Is a change log needed?
• Is a milestone set? Milestone must be set but we cannot check for it on Actions; do not let the green checkmark fool you.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (a8d4b56) 96.80% compared to head (ab8dc04) 96.80%.
Report is 2 commits behind head on master.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #370   +/-   ##
=======================================
  Coverage   96.80%   96.80%           
=======================================
  Files          17       17           
  Lines        2034     2034           
=======================================
  Hits         1969     1969           
  Misses         65       65           

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[pllim]

Hello! It looks like I did not configure the publish workflow to ever run for a PR. Maybe let me fix that and then you can rebase, so we know it works before merge? Thanks for your patience!

[neutrinoceros]

sure, by all means !

[neutrinoceros]

@pllim thanks for updating this branch. I think the failure is unrelated, can you re-trigger the job ?

[pllim]

@neutrinoceros , they didn't fail. I cancelled them because I realized I needed to enable artifact upload/download also for non-release events. I am still debating with myself whether I should disable them again after it is proven or not.

[pllim]

Ah... I mixed the release env stuff into dist build job too. I need to ponder this. (#371)

[pllim]

Thanks! I added a commit to clean up my own tech debt. I think this is GTG now.

[pllim]

Also, yes, I thought about migrating to OpenAstronomy template but resisted because I got the Trusted Publishing already set up here and that does not play well with templating (yet).