[Feature]: Implementation of OCI image signature and SBOM attestation

[R3DRUN3]

Checklist

• I've searched for similar issues and couldn't find anything matching
• I've discussed this feature request in the K8sGPT Slack and got positive feedback

Is this feature request related to a problem?

No

Problem Description

At its current state, the project exhibits suboptimal supply chain management.
The generated OCI images for k8sgpt are neither signed nor attested.

Solution Description

The proposed solution suggests minimal adherence to these best practices, by signing and attesting the images using their SBOM as a predicate.

Benefits

Main benefits are:

1. Certify both image and SBOM provenance.
2. Have the SBOM available in the same registry as the image, enabling effortless downloading for all users.
3. Implementing specific admission policies with tools such as Kyverno and Sigstore Policy Controller.

Potential Drawbacks

No response

Additional Information

For an implementation reference on GitHub Actions, please refer to this.