fix(langchain): fix response action for HITL (#33131)
Multiple improvements to HITL flow:
* On a `response` type resume, we should still append the tool call to
the last AIMessage (otherwise we have a ToolResult without a
corresponding ToolCall)
* When all interrupts have `response` types (so there's no pending tool
calls), we should jump back to the first node (instead of end) as we
enforced in the previous `post_model_hook_router`
* Added comments to `model_to_tools` router so clarify all of the
potential exit conditions
Additionally:
* Lockfile update to use latest LG alpha release
* Added test for `jump_to` behaving ephemerally, this was fixed in LG
but surfaced as a bug w/ `jump_to`.
* Bump version to v1.0.0a10 to prep for alpha release
---------
Co-authored-by: Sydney Runkle <sydneymarierunkle@gmail.com>
Co-authored-by: Sydney Runkle <54324534+sydney-runkle@users.noreply.github.com>
