Fix tests

[fnesveda]

I originally wanted to do a simple change to migrate the secrets used in the tests in CI to use organization-level secrets instead of repo-level ones. But when I was doing that change, I found out the template tests don't work at all, so I got into a very deep rabbit hole and I had to rewrite them basically from scratch.

This:

• migrates the secret used in CI to be sourced from organization-level secrets
• updates packages
• removes some old dead code
• adds linting to CI
• rewrites template tests to actually work
  • installs dependencies for both Node and Python templates
  • runs the template and actually checks if the run succeeded or not
• runs the tests in CI on Windows and Linux, with various Node and Python versions

There are still some issues:

• I had to disable linting of templates, because their lint was broken, I will fix it later when there aren't changes being made to the templates, to prevent conflicts
• Apify CLI returns exit code 0 even if the command fails, so it can't be relied on yet, I will fix it there and then update the tests here

[mnmkng]

Looks good. I trust that it works now 😄

[drobnikj]

👏

[jbartadev]

Nice, good job