added s390x support and created github action workflow

[rajnish-jauhari]

Added github workflow action to build multiarch images and added s390x architecture in the Makefile as well
cc: @hash-d

[hash-d]

This is not the best way to go about the login. Please look into using docker/login-action, instead, please

https://github.com/docker/login-action

[hash-d]

There is a makefile with build and push instructions, which uses podman. Is there a reason you're doing the CI build using Docker, instead?

Using the Makefile for build and push would make sure whatever a user builds locally is consistent with what the CI would produce.

[rajnish-jauhari]

@hash-d made the changes as requested by you

[hash-d]

Rajnish, I have added the user/token secrets, so when this is merged it should be good to push to Quay.

However, I think the on clause is too broad as it is. We do not want to push to quay on every git push. Please take a look at that, and we should be good to merge next.

[hash-d]

With this setting, I believe the workflow will run on any pushes, in any branches. That's probably not what we want. If we were only testing, that would be fine. But we're pushing to Quay, so we want it to run only on successful merges. I believe if you add branches: [main] here we should be good.