Add token-permissions to CI workflow

[lucacome]

Proposed changes

Problem: Permissions were not set for the CI workflow

Solution: Add permissions to the workflow to limit the scope of the GITHUB_TOKEN and grant only the extra permissions needed for the specific job. This also removes the separate release job and requires tests to pass before executing the release step.

Closes #837

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

[sjberman]

So the release draft step is now nested under the build binary step?

[lucacome]

@sjberman it was in the binary step before, then I moved it to its own job to wait for the tests, but I don't think it makes sense to create an additional job for the release. Also it's a requirement for the build on release, but because the job is skipped on PRs we can't enforce it in the build job.
I think having it as part of the build and just adding unit-tests, njs-unit-tests as a requirement for the job makes more sense. What do you think?

[sjberman]

LGTM

conformance tests were moved to a different workflow