absorb: run cleanupnodes() within transaction also when not using obsmarkers scmutil.cleanupnodes() schedules stripping to be done after the current transaction, so we can safely run it within the transaction. This also means that the phase will be updated within the transaction, which I believe means that the initial (possibly incorrect) phase will not visible. Differential Revision: https://phab.mercurial-scm.org/D6037