Use `{{ stdlib("c") }}`

[conda-forge-admin]

Fixes https://github.com/conda-forge/miktex-feedstock/issues/32

Adds {{ stdlib("c") }} to requirements/build

[conda-forge-webservices[bot]]

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) and found it was in an excellent condition.

I do have some suggestions for making it better though...

For recipe:

• License is not an SPDX identifier (or a custom LicenseRef) nor an SPDX license expression.

Documentation on acceptable licenses can be found here.

• 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 https://github.com/conda-forge/conda-forge.github.io/issues/2102.

[conda-forge-webservices[bot]]

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) and found it was in an excellent condition.

I do have some suggestions for making it better though...

For recipe:

• License is not an SPDX identifier (or a custom LicenseRef) nor an SPDX license expression.

Documentation on acceptable licenses can be found here.

[jakirkham]

@conda-forge-admin , please re-render

[jakirkham]

@conda-forge-admin , please restart CI