mathlib3

cf648606 - chore(*): remove 'using_well_founded wf_tacs', fixed in core (#2280)

chore(*): remove 'using_well_founded wf_tacs', fixed in core (#2280) Co-authored-by: Scott Morrison <scott.morrison@anu.edu.au> Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>