[CI] CI build fails in forks

[4TT1L4]

Problem:

• The CI build fails for fork repositories.

buildx failed with: ERROR: failed to solve: failed to push ghcr.io/geniusyield/smart-order-router:latest: unexpected status from POST request to https://ghcr.io/v2/geniusyield/smart-order-router/blobs/uploads/: 403 Forbidden

Solution:

• Make sure to push to the right container registry and don't try to push the container image to the GeniusYield GitHub Container Registry, since this is going to fail when attempted from repository forks.

[4TT1L4]

We are getting there, but #48 did not solve the issue.

Now we are getting a different error message in the repository forks:
https://github.com/4TT1L4/smart-order-router/actions/runs/6768359183

buildx failed with: ERROR: invalid tag "ghcr.io/4TT1L4/smart-order-router:latest": repository name must be lowercase

[4TT1L4]

It turns out that the docker/metadata-action action can handle repository naming.

We just need to use it.

Implemented in the following PR:

• [CI] CI build fails in forks #47 #50

[4TT1L4]

Now the build is working in the fork repositories, but the image tagging is a bit off.

I have created a new fix to tag the images build from main with latest:

• [CI] CI build fails in forks #47 #51

[4TT1L4]

Now the tagging is also working. The image build from the main branch is tagged with latest.

We might need a more sophisticated tagging and release process in the future, but for now the bare minimum should be fine.

I have tested this in my own fork of the repository:
https://github.com/4TT1L4/smart-order-router/pkgs/container/smart-order-router

See the following GitHub Actions run for details:
https://github.com/4TT1L4/smart-order-router/actions/runs/6782570186