Fix or remove CircleCI build

[ina-stoyanova]

Currently we've got a Github check running the project in CircleCI, but we don't actually have it configured. As part of this issue, we should:

• make a decision if we want a CircleCI pipeline to run - e.g. some terraform validate steps, or some other relevant steps
• if yes, then add a configuration file & make sure it passes
• if no, then disable this check for the project from CircleCI here

Why? Currently, almost every PR in this repo is appearing with a broken build because of the missing CircleCI configuration. This is not a big problem, so this task is more a housekeeping type of job.