Use latest distribution image as internal docker registry

[kwiatekus]

Description
Assess compatibility of the current configuration (chart) with the latest stable distribution version.
https://github.com/distribution/distribution/releases

• sync the distribution image into kyma registry via image-syncer
• Make necessary changes in the chart so that update of the Docker Registry container image to the latest version is possible.
• Update security configuration (sec-scan-config file)

Reason
We need to upgrade our internal Docker Registry workload to the latest version of CNCF distribution to ensure compatibility with modern tools, security enhancements, and performance improvements.

Related issues
kyma-project/kyma#18555

[pPrecel]

Compatibility check:

I've checked our docker-registry chart with the newer registry image (registry:3.0.0-alpha.1) and it's working really well.

• The new registry is OK with old images in PVC (built by the old registry)
• Functions are up and running (kaniko can push, k8s can pull images)
• Security aspects are still on the please (still secret with username and password are needed to push/pull image)
• The new cli (v3) can work with this registry (image-import)

The only doubt I see is that the registry 3.0.0 is still in alpha stage and we should not use it on production (or even for dev purposes) because API can be still changed and everything I describe above may not work.

[pPrecel]

Right now it's not possible to simply migrate to image-syncer because used by our image of docker-registry has an additional apache2-utils package installed we use to generate htpasswd file. I see a possibility to create a new image with apache2-utils installed on Alpine Linux and use it as an init container for the registry. But it needs more love and care than simply change the registry image name.