chore(deps): bump @langchain/core in the langchain group (#5198)

Bumps the langchain group with 1 update: [@langchain/core](https://github.com/langchain-ai/langchainjs).


Updates `@langchain/core` from 1.2.3 to 1.2.4
- [Release notes](https://github.com/langchain-ai/langchainjs/releases)
- [Commits](https://github.com/langchain-ai/langchainjs/compare/@langchain/core@1.2.3...@langchain/core@1.2.4)

---
updated-dependencies:
- dependency-name: "@langchain/core"
  dependency-version: 1.2.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: langchain
...

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Author: dependabot[bot]