Delete the unused schema.gql introspection document

[glen-84]

Summary

• Deletes Core/src/Types/Types/Introspection/schema.gql. Nothing reads it: schema.gql appears nowhere else in the repository, HotChocolate.Types.csproj has no .gql glob and no .props/.targets file adds one, and Types contains no manifest-resource load at all. It was the only tracked .gql file in the repository.
• The document had also drifted well behind the schema Hot Chocolate actually exposes, omitting __Schema.subscriptionType, __Type.specifiedByURL, __Type.isOneOf, __Type.appliedDirectives, __Directive.isRepeatable, the includeDeprecated argument on inputFields and directives, and 12 of the 19 __DirectiveLocation values. The introspection schema can be printed from a built schema, so a second copy in the tree earns nothing.

Test plan

• HotChocolate.Types builds clean after the deletion.
• Searched the repository, website included, for schema.gql and for .gql globs in project and build files. No references anywhere.

[Copilot]

Pull request overview

This PR removes a stale, unused GraphQL introspection schema document from the HotChocolate Core Types area, relying instead on generating/printing the introspection schema from the built runtime schema.

Changes:

• Deletes schema.gql under Types/Introspection.
• Removes the only tracked .gql document in the repository.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.