Update langgraph-checkpoint requirement in /libs/langgraph-store-mongodb

Updates the requirements on [langgraph-checkpoint](https://github.com/langchain-ai/langgraph) to permit the latest version.
- [Release notes](https://github.com/langchain-ai/langgraph/releases)
- [Commits](langchain-ai/langgraph@checkpoint==2.0.23...checkpoint==3.0.1)

---
updated-dependencies:
- dependency-name: langgraph-checkpoint
  dependency-version: 3.0.1
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

libs/langgraph-store-mongodb/pyproject.toml

@@ -9,7 +9,7 @@ description = "MongoDB implementation of the LangGraph long-term memory store."
 readme = "README.md"
 requires-python = ">=3.10"
 dependencies = [
-    "langgraph-checkpoint>=2.0.23,<3.0.0",
+    "langgraph-checkpoint>=2.0.23,<4.0.0",
     "langchain-mongodb>=0.6.1",
 ]