Introduces an automated system to detecting and manage incorrect imports
from `langchain_core` in favor of using the re-exports from `langchain`.
* Added `check-import-mappings.yml` workflow to periodically analyze the
latest version of `langchain_core`, check for re-exports in `langchain`
(and generate `import_mappings.json`), and automatically create PRs to
update the mappings cache in this repo.
* Added `check_import_mappings.py` to fetch latest package releases,
introspect `langchain` public `__init__` files, and generate a detailed
mapping of re-exported members from `langchain_core`. Uses the previous
local `import_mappings.json`
* Added `check-pr-imports.yml` workflow to run on PRs, ensuring inbound
contributions use `langchain` imports when available, and comment on PRs
with specific guidance if issues are found.
* Uses `check_pr_imports.py` to analyze PR diffs against the import
mappings, detect incorrect `langchain_core` imports, and output
suggested fixes for contributors.
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Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Mason Daugherty