docker file error

when you try installing detectron2 locally on windows it gives you CUDA error though toolkit is installed and it can identify system GPU.
i tried installing it from the docker file and I am getting python version mismatch errror.

to reproduce the issue
```
git clone https://github.com/facebookresearch/detectron2.git
cd detectron2
docker build -t detectron2 -f docker/Dockerfile .
```
RUN pip install --user -e detectron2_repo (when docker runs this it will throw python mismatch error)

Start with docker/Dockerfile and reproduce the reported build using the git clone, docker build, and pip install commands in the issue. Compare the Python version expected by the Docker image with the version used by detectron2, and also note the Windows/CUDA environment details that are missing. Done means the Docker build completes without the reported Python mismatch.

Written by the indexing model from the issue text.