Migrate docker image workflow to GAR

[amrit110]

Is your feature request related to a problem? Please describe.

We should move away from using dockerhub to store docker images and use our internal Google Artifact Registry

Describe the solution you'd like

• Setup internal GAR repository for vector-inference
• Adjust the current .github/workflow/docker.yml file to remove deployment and pushing to use internal GAR
• Enhance the workflow to also convert the docker image to singularity container and push that as an artifact to GAR as well
• Test the deployment, and then pull the corresponding images from GAR to both bonecho and killarney and test there.

Describe alternatives you've considered

NA

Additional context

NA