Add post-release validation job to release workflow

[timflannagan]

Add a post-release validation job to our release workflow to ensure that our release artifacts are functionally correct. Specifically, once a release is published, the job should:

1. Pull Down Release Assets

   • Download the freshly released artifacts (e.g., container images, manifests, etc.).

2. Deploy in a Kind Cluster

   • Spin up a temporary Kubernetes-in-Docker (Kind) cluster and apply the release artifacts.

3. Run Conformance Tests

   • Execute a conformance suite (or our chosen test suite) against the deployed artifacts to validate they meet expected functionality.

By adding this post-release validation step, we can quickly confirm that our published releases are operational and meet our baseline quality standards without having to manually verify each release.