build(deps): bump langchain-core

Bumps [langchain-core](https://github.com/langchain-ai/langchain) from 0.3.51 to 0.3.81.
- [Release notes](https://github.com/langchain-ai/langchain/releases)
- [Commits](langchain-ai/langchain@langchain-core==0.3.51...langchain-core==0.3.81)

---
updated-dependencies:
- dependency-name: langchain-core
  dependency-version: 0.3.81
  dependency-type: direct:production
...

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

Author: dependabot[bot]

cloud-infrastructure/compute-including-hpc/ai-infra-gpu/ai-infrastructure/rag-langchain-vllm-mistral/files/requirements.txt

@@ -76,7 +76,7 @@ jsonschema==4.23.0
 jsonschema-specifications==2024.10.1
 langchain==0.3.23
 langchain-community==0.3.21
-langchain-core==0.3.51
+langchain-core==0.3.81
 langchain-huggingface==0.1.2
 langchain-text-splitters==0.3.9
 langsmith==0.3.28