Fix dependency versions for langchain and pydantic compatibility

requirements.txt

@@ -1,18 +1,19 @@
 --find-links https://download.pytorch.org/whl/torch_stable.html
-torch==2.0.1
-torchvision==0.15.2
+torch==2.0.1+cpu
+torchvision==0.15.2+cpu
 torchaudio==2.0.2+cpu
 transformers==4.31.0
 numpy>=1.23.5
 scikit-learn>=1.2.2
 scipy>=1.10.1
-nltk>=3.8.1
+pandas>=2.0.2
 sentence-transformers==2.2.2
 tqdm>=4.65.0
 gradio==3.40.1
 duckduckgo-search==3.8.5
 beautifulsoup4==4.12.2
-langchain==0.0.262
+langchain==0.0.335
+pydantic==1.10.13
 lxml==4.9.3
 requests==2.31.0
 protobuf==4.25.1