chore(deps): update dependency langchain-core to v1.2.0 (#465)

Author: renovate-bot

packages/toolbox-langchain/requirements.txt

@@ -1,5 +1,5 @@
 -e ../toolbox-core
-langchain-core==1.1.3
+langchain-core==1.2.0
 PyYAML==6.0.3
 pydantic==2.12.5
 aiohttp==3.13.2