feat(frontends/lean/structure_cmd): avoid unnecessary local_ref
feat(frontends/lean/structure_cmd): avoid unnecessary local_ref

leodemoura/lean,fpvandoorn/lean,Kha/lean,Kha/lean,leanprover/lean,johoelzl/lean,johoelzl/lean,fgdorais/lean,fgdorais/lean,rlewis1988/lean,leanprover/lean,avigad/lean,Kha/lean,digama0/lean,rlewis1988/lean,dselsam/lean,dselsam/lean,fpvandoorn/lean,leanprover/lean,johoelzl/lean,rlewis1988/lean,dselsam/lean,digama0/lean,leodemoura/lean,fpvandoorn/lean,avigad/lean,leanprover-community/lean,fpvandoorn/lean,leodemoura/lean,rlewis1988/lean,dselsam/lean,fpvandoorn/lean,leanprover-community/lean,avigad/lean,rlewis1988/lean,fgdorais/lean,johoelzl/lean,fgdorais/lean,leanprover/lean,digama0/lean,leanprover-community/lean,fgdorais/lean,leanprover-community/lean,leanprover-community/lean,digama0/lean,Kha/lean,johoelzl/lean,johoelzl/lean,leodemoura/lean,leanprover/lean,leanprover/lean,leanprover-community/lean,fpvandoorn/lean,rlewis1988/lean,Kha/lean,digama0/lean,fgdorais/lean,avigad/lean,leodemoura/lean,avigad/lean,dselsam/lean,digama0/lean,avigad/lean,leodemoura/lean,Kha/lean,dselsam/lean