ci: Add release github action

**What**

Add a new github action that automates the release steps defined [here](https://github.com/Kuadrant/dns-operator/blob/main/docs/RELEASE.md).

Other repos have a similar [task](https://github.com/Kuadrant/limitador-operator/blob/main/.github/workflows/release.yaml), but note this repo isn't creating a branch per patch release like all the others. Not really sure why they went that way.

Start by reading docs/RELEASE.md to list the release steps, then compare the referenced limitador-operator .github/workflows/release.yaml workflow with this repository's existing workflows. Define the workflow so it automates the documented release process without assuming a branch per patch release. Done means the release steps are reproducibly handled by GitHub Actions and the workflow is validated against this repository's release conventions.

Written by the indexing model from the issue text.