Allow YAML format for .netkans

[HebaruSan]

Motivation

See KSP-CKAN/CKAN#3367, we might want to allow .netkans to use YAML format. If so, our pull request validation Action will need to be able to handle that.

Changes

Now if a file is a .netkan, we use yamllint instead of jsonlint to validate its syntax.

Parsing of these files for our own use is taken care of in KSP-CKAN/NetKAN-Infra#219.

This should allow a pull request to be submitted to the NetKAN repo using YAML format with correct validation.

[DasSkelett]

One issue I see by choosing the linting tool based on file extension is that internal ckans might create problems. According to KSP-CKAN/CKAN#3367 they are allowed to be YAML, but here we'd require them to be JSON, right?

[HebaruSan]

One issue I see by choosing the linting tool based on file extension is that internal ckans might create problems. According to KSP-CKAN/CKAN#3367 they are allowed to be YAML, but here we'd require them to be JSON, right?

I don't think this can validate an internal .ckan file. It would have to be running in a mod's own repo, meaning it would use source=netkans mode, so only files with a .netkan extension would be checked. Files with a .ckan extension can only be validated in source=commits mode, where we want it to not allow YAML because CKAN-meta shouldn't have YAML.

[DasSkelett]

Yeah I guess as long as they always stick to source=netkans they're fine, and there aren't many internal ckans anyway.