fix type error on link.raw

[cometkim]

Types of changes

• Chore (a non-breaking change which is related to package maintenance)
• Bug fix (a non-breaking change which fixes an issue)
• New feature (a non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Description

There is type error on PrismicLinkType so build fails when using raw field.

The field "PrismicLinkField.raw." was explicitly defined as non-nullable via the schema customization API (by yourself or a plugin/theme). This means that this field is not optional and you have to define a value. If this is not your desired behavior and you defined the schema yourself, go to "createTypes" in gatsby-node.

This causes because there is no raw field in actual data. It should be virtually provided for field data.

Checklist:

• My change requires an update to the official documentation.
• All TSDoc comments are up-to-date and new ones have been added where necessary.
• All new and existing tests are passing.