Improve error display

[jonashaag]

When I put in a missing dependency and click on GHA I'm greeted with this:

Then when I open the first red section I get

Opening the last step gets me to this

We might want to look into improving the UX here.

[pavelzw]

#160 removes the nodejs stacktrace. We might want to not fail in the post step but only print a warning if it already failed in the main step.