Failing to checkout out a revision with an unknown base

[suhaibmujahid]

Example: https://hackbot.moz.tools/runs/16d4c648-693f-4073-be6f-c5ce5aa42b25

In this case it is a stack where the first revision in the stack is based on a commit that seem to not be in the repo.

UnresolvedCommitError: Cannot expand 0a336b1a481b to a full commit hash: Diffusion does not know one; the commit may not be imported, e.g. an unlanded parent of a stacked patch.

Related: https://bugzilla.mozilla.org/show_bug.cgi?id=2068637