Update GitHub actions

[giffels]

This pull requests addresses warnings about the migration of GitHub actions from nodejs:12 to nodejs:16.

Like

setup-docker-builds
Node.js 12 actions are deprecated. Please update the following actions to use Node.js 16: actions/checkout@v2. 
For more information see: 
https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/.

and

 setup-docker-builds
The `set-output` command is deprecated and will be disabled soon. Please upgrade to using Environment Files. 
For more information see: 
https://github.blog/changelog/2022-10-11-github-actions-deprecating-save-state-and-set-output-commands/

[codecov-commenter]

Codecov Report

Base: 98.88% // Head: 98.88% // No change to project coverage 👍

Coverage data is based on head (d6ee17d) compared to base (248cd6e).
Patch has no changes to coverable lines.

Additional details and impacted files

@@           Coverage Diff           @@
##           master     #282   +/-   ##
=======================================
  Coverage   98.88%   98.88%           
=======================================
  Files          56       56           
  Lines        2328     2328           
=======================================
  Hits         2302     2302           
  Misses         26       26           

Help us with your feedback. Take ten seconds to tell us how you rate us. Have a feature suggestion? Share it here.

☔ View full report at Codecov.
📢 Do you have feedback about the report comment? Let us know in this issue.

[RHofsaess]

Should be fine if the tests are okay with it :D
👍

[rfvc]

Thanks for updating the actions, @giffels. As the checks you updated are all green and this is addressed in #279, I'm fine with merging.