Add missing dependency of tree_sitter_languages and update the CONTRIBUTING.md...

Add missing dependency of tree_sitter_languages and update the CONTRIBUTING.md to install data_requirements (#7870)

CONTRIBUTING.md

@@ -317,6 +317,7 @@ For bigger changes, you'll want to create a unit test. Our tests are in the `tes
 We use `pytest` for unit testing. To run all unit tests, run the following in the root dir:
 
 ```bash
+pip install -r data_requirements.txt
 pytest tests
 ```
 

setup.py

@@ -29,6 +29,7 @@ install_requires = [
     "beautifulsoup4",  # hotfix for langchain 0.0.212 bug
     "nest_asyncio",
     "nltk",
+    "tree_sitter_languages",
 ]
 
 setup(