improve ignore_run_exports, don't refer to -ng packages

[conda-forge-admin]

Xref: conda-forge/ctng-compilers-feedstock#148

Fixes #61

[conda-forge-webservices]

Hi! This is the friendly automated conda-forge-linting service.

I wanted to let you know that I linted all conda-recipes in your PR (recipe/meta.yaml) and found some lint.

Here's what I've got...

For recipe/meta.yaml:

• This recipe is using a compiler, which now requires adding a build dependence on {{ stdlib("c") }} as well. Note that this rule applies to each output of the recipe using a compiler. For further details, please see META: {{ stdlib("c") }} migration conda-forge.github.io#2102.

[conda-forge-webservices]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe/meta.yaml) and found it was in an excellent condition.

[jan-janssen]

Looks good to me