Triage tool deals with non-linear history

[Steboss]

If commits do not lie on the same linear git history. The tool would use git fetch because it couldn't find a direct path between the passing and failing commits.
Here the changes introduce a new logic to find the correct bisection range:

• apply git merge-base to identify common ancestors between the passing and failing commit
• at build-and-run stage we're checking out the base commit from the main branch, and we apply cherry-pick for all new relevant features