Welcome to the forum! CircleCI provides an ephemeral execution environment in which you can pull code and execute tasks in a pipeline. We do not offer any testing tools directly but provide the platform for you to implement any tool or library.
We also have Orbs! Orbs are bits of pre-made config you can inject into your config that sometimes contain tools that may make it easier to test, deploy and more: https://circleci.com/orbs/registry/
It looks like you could likely use our NodeJS docker image and write a small node app to accomplish this: https://www.npmjs.com/package/jsonschema