fix(deps): update dependency langchain to v1

[renovate]

This PR contains the following updates:

Package	Change	Age	Confidence
langchain (source, changelog)	^0.3.13 -> ^1.0.0

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[renovate]

⚠️ Artifact update problem

Renovate failed to update an artifact related to this branch. You probably do not want to merge this PR as-is.

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• any of the package files in this branch needs updating, or
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The artifact failure details are included below:

File name: poetry.lock

Updating dependencies
Resolving dependencies...


Because no versions of langchain match >1.0.0,<1.0.1 || >1.0.1,<1.0.2 || >1.0.2,<2.0.0
 and langchain (1.0.0) depends on langgraph (>=1.0.0,<1.1.0), langchain (>=1.0.0,<1.0.1 || >1.0.1,<1.0.2 || >1.0.2,<2.0.0) requires langgraph (>=1.0.0,<1.1.0).
And because langchain (1.0.1) depends on langgraph (>=1.0.0,<1.1.0)
 and langchain (1.0.2) depends on langgraph (>=1.0.0,<1.1.0), langchain (>=1.0.0,<2.0.0) requires langgraph (>=1.0.0,<1.1.0).
So, because learn-ai depends on both langchain (^1.0.0) and langgraph (^0.6.6), version solving failed.