Add automation for SSDLC scans on release

We should generate the required security scan reports on release, following an approach like [the one used by ops](https://github.com/canonical/operator/blob/main/.github/workflows/sbom-secscan.yaml). Ideally uploading the reports would be automated too, but if that's still tricky consider creating a follow-up 'rainy day' issue for it.

Start by reading the referenced .github/workflows/sbom-secscan.yaml in canonical/operator, then inspect charmlibs' release workflow files. Identify which SSDLC reports are required and when releases run; done means the reports are generated on release, with upload automation treated as optional or a follow-up.

Written by the indexing model from the issue text.