chore(library/cache_helper): remove dead code
chore(library/cache_helper): remove dead code

Kha/lean,Kha/lean,leanprover/lean,fpvandoorn/lean,leodemoura/lean,leanprover/lean,digama0/lean,leodemoura/lean,dselsam/lean,Kha/lean,fpvandoorn/lean,Kha/lean,leanprover/lean,dselsam/lean,digama0/lean,leanprover-community/lean,dselsam/lean,leodemoura/lean,dselsam/lean,fpvandoorn/lean,leodemoura/lean,digama0/lean,leanprover/lean,leanprover-community/lean,leanprover-community/lean,Kha/lean,Kha/lean,fpvandoorn/lean,digama0/lean,dselsam/lean,leodemoura/lean,fpvandoorn/lean,dselsam/lean,leanprover-community/lean,leanprover/lean,fpvandoorn/lean,digama0/lean,leanprover-community/lean,leanprover/lean,leodemoura/lean,digama0/lean,leanprover-community/lean