fix(deps): bump @langchain/core from 0.3.75 to 0.3.80

Bumps [@langchain/core](https://github.com/langchain-ai/langchainjs) from 0.3.75 to 0.3.80.
- [Release notes](https://github.com/langchain-ai/langchainjs/releases)
- [Commits](https://github.com/langchain-ai/langchainjs/commits)

---
updated-dependencies:
- dependency-name: "@langchain/core"
  dependency-version: 0.3.80
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

package-lock.json

@@ -27,7 +27,7 @@
   "dependencies": {
     "@langchain/langgraph": "^0.4.9",
     "@langchain/langgraph-checkpoint": "^0.0.11",
-    "@langchain/core": "^0.3.28",
+    "@langchain/core": "^0.3.80",
     "@modelcontextprotocol/sdk": "^1.24.0",
     "pino": "^9.9.5",
     "zod": "^3.25.67",