LangGraph 3.1.2

Changes since checkpointsqlite==3.1.1

• release(checkpoint-sqlite): 3.1.2 (#9288)
• fix(checkpoint-postgres,checkpoint-sqlite): treat an empty checkpoint_id as the latest in delta history (#9262)
• fix(checkpoint,checkpoint-postgres,checkpoint-sqlite): validate namespace labels before store dispatch (#9217)
• fix: order delta channel replay by task path (#8544)
• chore(deps-dev): bump the minor-and-patch group in /libs/checkpoint-sqlite with 3 updates (#9146)
• chore(deps): bump urllib3 from 2.7.0 to 2.8.0 in /libs/checkpoint-sqlite (#9135)
• fix(checkpoint-sqlite): walk delta ancestors by parent pointer (#8557)
• chore(deps): bump anyio from 4.12.1 to 4.14.2 in /libs/checkpoint-sqlite (#8993)
• chore(deps-dev): bump the minor-and-patch group in /libs/checkpoint-sqlite with 2 updates (#8772)
• fix(checkpoint): widen Store put value type to Mapping[str, Any] (#8617)
• release(checkpoint): 4.2.0 (#8563)
• test(checkpoint-postgres,checkpoint-sqlite): run the conformance suite (#8537)
• chore: enable RUF100 and clear unused noqa directives (#8546)
• chore(checkpoint-postgres,checkpoint-sqlite): enable PLC0415 lint rule (#8540)
• chore(deps): bump the minor-and-patch group in /libs/checkpoint-sqlite with 4 updates (#8494)