Just replacing `depends_on 'autoconf' => [:recommended, :run]` by `depends_on 'autoconf' => :recommended` introduces the following errors on `brew audit pyenv` because `autoconf` and `pkg-config` are listed in `FormulaAuditor::BUILD_TIME_DEPS`. Am I missed something?

```
% brew audit pyenv
pyenv:
 * autoconf dependency should be "depends_on 'autoconf' => :build"
 * pkg-config dependency should be "depends_on 'pkg-config' => :build"

Error: 2 problems in 1 formulae
```