fix(types): include web_search_call.action.sources in ResponseIncludable

[SkinnnyJay]

Changes being requested

Adds missing type support for the documented include value to resolve TypeScript compile errors without affecting runtime behavior.

Core changes:

• Extend ResponseIncludable to include 'web_search_call.action.sources'.
• File touched: src/resources/responses/responses.ts (surgical one-line union addition).

Test coverage:

• Add a long-term invariant test to ensure the includable literal is accepted and arbitrary strings are rejected: tests/responses.includable.test.ts.
• Remove temporary tests under tests/temp/* after validating the fix.

Additional context & links

Bug: #1645

This addresses TypeScript errors when using the documented include 'web_search_call.action.sources' in the Responses API.

Problem:
The OpenAPI description listed the value, but the enum omitted it. The SDK’s generated types mirror the enum, so the literal was missing and caused the TS compile
failures.

Solution:
Include the missing literal in ResponseIncludable and add focused tests to prevent regressions. This is a minimal, type-only change with no runtime impact.

Impact:

• ✅ Restores type-safety for the documented include
• ✅ No runtime behavior changes
• ✅ Minimal, surgical change
• ✅ Tests added to guard against regressions

✅ I understand that this repository is auto-generated, and my pull request may not be merged

[SkinnnyJay]

Ready for review..