Update Dockerfile to fix broken OpenCV installation

Dockerfile

@@ -26,8 +26,7 @@ RUN python -m venv /venv && \
     /venv/bin/pip install --no-cache-dir -r requirements.txt
 
 # Fix broken OpenCV installation for docker container
-RUN apt-get install -y libgl1
-RUN apt-get install -y python3-opencv 
+RUN apt-get update && apt-get install -y libgl1 && apt-get install -y python3-opencv 
 # RUN /venv/bin/pip install opencv-python
 
 # Set user back to non-root