Allow passing only a subset of the state in the ToolRuntime

### Checked other resources - [x] This is a feature request, not a bug report or usage question. - [x] I added a clear and descriptive title that summarizes the feature request. - [x] I used the GitHub search to find a similar feature request and didn't find it. - [x] I checked the LangChain documentation and API reference to see if this feature already exists. - [x] This is not related to the langchain-community package. ### Feature Description I would like LangChain to support passing only a subset of the graph state to a tool function via ToolRuntime. ### Use Case Using ToolRuntime currently entails passing the entire state to the tool function, which can include a lot of extraneous data. It's also hard to understand from the function signature what aspects of the graph the tool depends on. ### Proposed Solution _No response_ ### Alternatives Considered You can still use InjectedState, but given the encouraged shift towards ToolRuntime it would be great to have this in the latter. ### Additional Context _No response_