mathlib

2b6b9ffc - feat(category_theory/abelian/derived): add left_derived_zero_iso_self (#12403)

feat(category_theory/abelian/derived): add left_derived_zero_iso_self (#12403) We add `left_derived_zero_iso_self`: the natural isomorphism `(F.left_derived 0) ≅ F` if `preserves_finite_colimits F`. From lean-liquid Co-authored-by: @adamtopaz