CI stability enhancement.

We build graphscope image from the ubuntu:20.04 everytime, and we suffer from the network failure quite often when `apt install` or `wget hadoop`, and it takes quite some time.

I noticed that the image can be split into 2 parts, that we freeze the runtime dependency such as stuff installed by `apt` and `hadoop` files to a new base image, and the graphscope wheels can be installed from the base image.