monorepo: add script for updating notebook cassettes (#27399)

1. Move dependencies for running notebooks into monorepo poetry test
deps;
2. Add script to update cassettes for a single notebook;
3. Add cassettes for some how-to guides.

---

To update cassettes for a single notebook, run
`docs/scripts/update_cassettes.sh`. For example:
```
./docs/scripts/update_cassettes.sh docs/docs/how_to/binding.ipynb
```
Requires:
1. monorepo dev and test dependencies installed;
2. env vars required by notebook are set.

Note: How-to guides are not currently run in [scheduled
job](https://github.com/langchain-ai/langchain/actions/workflows/run_notebooks.yml).
Will add cassettes for more how-to guides in subsequent PRs before
adding them to scheduled job.

docs/scripts/update_cassettes.sh

@@ -0,0 +1,33 @@
+#!/bin/bash
+
+# Get the working directory from the input argument, default to 'all' if not provided
+WORKING_DIRECTORY=${1:-all}
+
+# Function to delete cassettes
+delete_cassettes() {
+  local dir=$1
+  if [ "$dir" == "all" ]; then
+    echo "Deleting all cassettes..."
+    rm -f docs/cassettes/*.msgpack.zlib
+  else
+    # Extract the filename from the directory path
+    local filename=$(basename "$dir" .ipynb)
+    echo "Deleting cassettes for $filename..."
+    rm -f docs/cassettes/${filename}_*.msgpack.zlib
+  fi
+}
+
+# Delete existing cassettes
+delete_cassettes "$WORKING_DIRECTORY"
+
+# Pre-download tiktoken files
+echo "Pre-downloading tiktoken files..."
+poetry run python docs/scripts/download_tiktoken.py
+
+# Prepare notebooks
+echo "Preparing notebooks for CI..."
+poetry run python docs/scripts/prepare_notebooks_for_ci.py --comment-install-cells --working-directory "$WORKING_DIRECTORY"
+
+# Run notebooks
+echo "Running notebooks..."
+./docs/scripts/execute_notebooks.sh "$WORKING_DIRECTORY"