[3.12] gh-120343: Do not reset byte_col_offset_diff after multiline tokens (GH-120352) (#120356)

(cherry picked from commit 1b62bcee941e54244b3ce6476aef8913604987c9)

Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>
Co-authored-by: blurb-it[bot] <43283697+blurb-it[bot]@users.noreply.github.com>