Merge branch 'pw/rebase-drop-notes-with-commit' into jch

The rebase post-rewrite notes-copying logic has been corrected. When a
commit is dropped during rebase (e.g., because its changes are already
upstream), we no longer record it as rewritten, preventing its notes
from being copied to an unrelated commit.

* pw/rebase-drop-notes-with-commit:
  amend! sequencer: simplify pick_one_commit()
  amend! sequencer: remove unnecessary "or" in pick_one_commit()
  fixup! sequencer: never reschedule on failed commit
  fixup! sequencer: be more careful with external merge
  sequencer: do not record dropped commits as rewritten
  sequencer: use an enum to represent result of picking a commit
  sequencer: return early from pick_one_commit() on success
  sequencer: simplify pick_one_commit()
  sequencer: remove unnecessary condition in pick_one_commit()
  sequencer: simplify handing of fixup with conflicts
  sequencer: remove unnecessary "or" in pick_one_commit()
  sequencer: never reschedule on failed commit
  sequencer: be more careful with external merge
  sequencer: move definition of is_final_fixup()
  t3400: restore coverage for note copying with apply backend

diff --cc sequencer.c
Simple merge