Two small changes to the workflows:
- Run linter and spellcheck workflows with LTS node version. The
advantage of this is that we no longer have to raise the node version
for them.
- Split "Run test" step into two steps for more clarity.
This has the advantage that the package manager is no longer involved
after the installation process.
However, previous start commands such as `npm run start` continue to
work. So we don't even have to adapt the documentation.
Besides updating cspell and handling spelling issues, the important
change is adding the spelling check to the GitHub workflow.
I'm not sure if it will bother us too much when people create PRs. But I
wanted to give it a try. Or do you have any other ideas on how we can
run the spelling check on a regular basis?
