fix(sdk): always attach Response on HTTPError (#2668)

## Summary
- Always pass `includeResponse: true` when converting failed `Response`
objects to `HTTPError`, so `error.response` is available without
registering `onFailedResponseHook`.

## Test plan
- [x] New unit test `should attach error.response without
onFailedResponseHook` passes with the fix
- [x] Same test fails with `response: undefined` when the fix is stashed
(`git stash` A/B)
- [x] Changeset for `@langchain/langgraph-sdk`

Fixes #2632

Co-authored-by: edenbuilds <279970382+edenbuilds@users.noreply.github.com>