Scalar types use explicit any, but their types are known

[jbreckel]

The currently used custom scalar types are all strings, as noted in the comments.

Using unknown instead of any would also be the type safe way as described here.

[zhouzi]

The fix proposed to this issue in #561 is part of my fork which is also published to npm, with automatic updates enabled:

• Forked repository: zhouzi/graphql-schema
• npm package: github-graphql-schema