Add renovate to pipeline to track job image updates

As the pipeline is now using approved Registry1 images for its jobs, we need to make sure these are updated when CHT releases new versions. An example is that CHT has update the ClamAV image twice, and we don't know about this until someone stumbles upon this. If we were to use Renovate on these images, we could automate tracking updates, and MRs to apply them to the pipeline.

Acceptance Criteria

• renovate.json file added to pipeline project
• Verify renovate-bot GL user has access to the pipeline project

a renovate configuration has been added.