fix: add tiktoken as required dependency in pyproject (#502)

pyproject.toml

@@ -85,6 +85,7 @@ python-dotenv = "^1.0.0"
 langchain = "^0.0.237"
 requests = "^2.31.0"
 openai = "^0.27.5"
+tiktoken = "^0.4.0"
 chromadb ="^0.4.2"
 youtube-transcript-api = "^0.6.1"
 beautifulsoup4 = "^4.12.2"
@@ -124,4 +125,3 @@ poe = ["fastapi-poe"]
 
 
 [tool.poetry.scripts]
-