Fix: pre-install Cython for youtokentome

Dockerfile

@@ -6,7 +6,7 @@ RUN apt-get update && apt-get install -y ffmpeg git && rm -rf /var/lib/apt/lists
 WORKDIR /app/chatbot
 COPY requirements.txt .
 ENV SKLEARN_ALLOW_DEPRECATED_SKLEARN_PACKAGE_INSTALL=True
-RUN apt-get update && apt-get install -y build-essential
+RUN pip install --no-cache-dir Cython
 RUN pip install --no-cache-dir -r requirements.txt
 
 # Create writable directories