feat(docker): Decouple UMA and Across Docker images

[dijanin-brat]

Motivation

Currently, UMA and Across bots are built in the same docker image. We want to decouple that so it speeds up the deployment process and give us more granular control of the two projects.

Summary

Deleted Across relayer repo from docker image.

Details

This may be unnecessary for some PRs. Catch-all for detailed explanations about the implementation decisions and implications of the change.

Testing

Check a box to describe how you tested these changes and list the steps for reviewers to test.

• [ ] Ran end-to-end test, running the code as in production
• [ ] New unit tests created
• [ ] Existing tests adequate, no new tests required
• [ ] All existing tests pass
• [ ] Untested

Issue(s)

Fixes #XXXX