Merge branch 'la/trailer-cleanups' into maint-2.43

Code clean-up.

* la/trailer-cleanups:
  trailer: use offsets for trailer_start/trailer_end
  trailer: find the end of the log message
  commit: ignore_non_trailer computes number of bytes to ignore

diff --cc builtin/commit.c
Simple merge

diff --cc builtin/merge.c
Simple merge

diff --cc commit.c
Simple merge

diff --cc sequencer.c
Simple merge

diff --cc trailer.c
Simple merge