Uses GraphQLSwift CI

[NeedleInAJayStack]

This switches to the centralized GraphQLSwift CI repo for better maintainability.

[Copilot]

Pull Request Overview

This PR switches the repository’s CI configuration to use the centralized GraphQLSwift CI workflows and updates several SubscribeField initializers to explicitly ignore an unused FieldType.Type parameter.

• Swap out local GitHub Actions in .github/workflows/build.yml for calls to the shared GraphQLSwift CI repo.
• Remove the old build.yml file and introduce .github/workflows/test.yaml that references the centralized lint and test workflows.
• Update multiple SubscriptionField convenience initializers to mark the FieldType.Type parameter as unused.

Reviewed Changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
Sources/Graphiti/Subscription/SubscribeField.swift	Changed as: FieldType.Type to as _: FieldType.Type to silence unused-parameter warnings
.github/workflows/test.yaml	Added workflow that uses GraphQLSwift/ci lint and test jobs
.github/workflows/build.yml	Removed local build workflow in favor of centralized CI

Comments suppressed due to low confidence (1)

Sources/Graphiti/Subscription/SubscribeField.swift:453

• The FieldType.Type parameter is now ignored (using _). If this parameter is no longer needed, consider removing it from the API to simplify the initializer signature and avoid confusion for users.

        as _: FieldType.Type,