Migrate pre-test-infra-validate-kaniko-build-config to GitHub Actions

[dekiel]

Description

The prowjob pre-test-infra-validate-kaniko-build-config tests changes in kaniko config. This should be migrated to the GitHub Actions. The image-builder reusable workflow does not accept an input parameter test-kaniko-build-config.

Path to the prowjob file: prow/jobs/kyma-project/test-infra/ado-validation.yaml

Reasons

Prow shutdown

Acceptance Criteria

Changes in kaniko-build-config are tested.

[Sawthis]

It was already migrated to Github action: https://github.com/kyma-project/test-infra/blob/main/.github/workflows/pull-validate-kaniko-build-config.yml