Fix errors when build docker

[QIU-Shuo]

Patch Description
Hi, the current Dockerfile cannot build successfully, I made a few fix for it.

1. Limit the max version for hydra-core, since hydra-core 1.2 will require omegaconf~=2.2 and raise a conflict.
2. Fix error in line 35.
3. I didn't encounter issue Public GPG key error NVIDIA/nvidia-container-toolkit#258, and the workaround in line 8-9 raises an file not found error for me. They have probably fixed the docker, but I am not sure about this.

Testing steps
docker build -f Dockerfile .

[suchenzang]

Thanks for the PR!