skip exits with 1 for the buildkite pr build analyser

Given https://github.com/elastic/ai-github-actions/blob/main/.github/workflows/gh-aw-estc-pr-buildkite-detective.md?plain=1

if skip then it fails

But that's not what I think we should use, we should skip the next steps instead of running the analysis any further.

If it fails then the job failed and it will get reported, while I don't think we should use this as is.

Analyse how we can improve this