Update outdated Konflux Tekton tasks based on enterprise contract verification warnings to resolve trusted task violations.

Tasks updated:

• buildah-remote-oci-ta: 0.5 digest update
• ecosystem-cert-preflight-checks: 0.2 digest update
• git-clone-oci-ta: 0.1 digest update
• prefetch-dependencies-oci-ta: 0.2 digest update
• push-dockerfile-oci-ta: 0.1 digest update

Files updated: 6 pipeline YAML files in .tekton/ directory

All updates are digest-only updates with no version changes.