Fix excludePNP parsing for GraphQL

[laggycomputer]

Description

As specified in the issue, excludePNP is broken for GraphQL grades endpoints. Zod expects a string, which is impossible when schema expects boolean. Fixed by coercing to string before parsing.

z.coerce.boolean() is unacceptable since Boolean("false") === true which is not what we want.

Related Issue

Fixes #62.

Motivation and Context

i just wanna use API man

How Has This Been Tested?

Tested with Postman on a local deployment.

Screenshots (if appropriate):

Schema validation still works, of course:

Types of changes

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

Checklist:

• My code involves a change to the database schema.
• My code requires a change to the documentation.