build: raise monorepo TypeScript floor to 5.2

[michaelgiraldo]

Summary

Raises the monorepo TypeScript/Jest tooling floor to TypeScript 5.2 and removes the need to rely on a temporary Disposable compatibility bridge for newer graphql-tools type declarations.

Why

The repo's previous TypeScript floor was older than the standard library support assumed by newer upstream dependencies. In particular, newer graphql-tools declarations reference the standard Disposable / AsyncDisposable globals introduced in TypeScript 5.2.

Changes

• upgrade the repo TypeScript/Jest/tooling versions needed for TS 5.2 compatibility
• remove the need for a package-local Disposable compatibility shim by moving the repo to a toolchain that natively understands those globals
• modernize affected Jest config in amplify-codegen, graphql-generator, graphql-types-generator, graphql-docs-generator, appsync-modelgen-plugin, and the e2e packages
• update snapshots where required by the Jest 29 serialization changes
• tighten the generator utility APIs so optional closures are modeled as optional instead of requiring placeholder no-op callbacks
• keep the stricter test/lint cleanup package-local rather than broadening repo rules

Non-goals

• does not replace the package-owned dependency-chain fixes in fix(graphql-types-generator): remove babel 6 runtime chain #1012 or fix(appsync-modelgen-plugin): replace relay 12 dependency chain #1013
• does not claim to resolve the downstream fresh-install issue in a lot of vulnerabilities amplify-backend#3135 by itself

Validation

Validation on this stacked branch completed locally:

• npx -y yarn@1.22.22 lint
• npx -y yarn@1.22.22 build
• npx -y yarn@1.22.22 jest --runInBand
• npx -y yarn@1.22.22 workspace @aws-amplify/graphql-types-generator test --runInBand
• npx -y yarn@1.22.22 workspace @aws-amplify/amplify-codegen-e2e-core build

AWS-backed PR/e2e workflows were not run locally in this environment. This repo appears to validate that layer through the existing CodeBuild PR workflow, so maintainer/CI validation is still requested for the cloud-backed checks.

Maintainer Context

This PR is intentionally stacked on #1013.

The repo-wide TypeScript/Jest toolchain migration in this PR does not currently build cleanly on main without the appsync-modelgen-plugin scalar-map and visitor updates from #1013. Because of that dependency, this PR is being proposed as the next layer on top of #1013 rather than as an independently mergeable branch today.

If #1013 is merged first, I can respin this PR onto the updated main so the diff shows only the toolchain changes.

Maintainer Ask

Please review this as the stacked repo-wide toolchain follow-up to #1013. Local lint/build/unit coverage is green on this branch; cloud-backed PR validation is still requested through the existing PR workflow / CodeBuild path.