Cancelled GitHub CI rerun after success is treated as failure #633

PR: nodejs/node#43085
Action rerun attempt: https://github.com/nodejs/node/actions/runs/2320332585/attempts/7
git-node land output: nodejs/node#43085 (comment)

At the moment of landing, the latest run of that action was cancelled, there were 5 prior successful runs, and GitHub UI reported everything as green.
However, ncu treated it as Last GitHub CI failed error, which is either wrong (not sure if easily fixable, as it requires failproof checking previous attempts) or confusing (Last GitHub CI cancelled might be a better error message).

Details: in PRChecker.checkGitHubCI(), commit.checkSuites.nodes[2] for this case was

  {
    app: { slug: 'github-actions' },
    conclusion: 'CANCELLED',
    status: 'COMPLETED'
  }