Add support for standard SBOM formats

[sambhav]

As of Buildpacks API 0.7, we started supporting standard SBOM formats including CycloneDx, SPDX and Syft. This is a feature request to update Heroku buildpacks/builders to output at least one of these SBOMs during builds. For more information please check out -

https://github.com/buildpacks/spec/releases/tag/buildpack%2Fv0.7
https://github.com/buildpacks/spec/releases/tag/platform%2Fv0.8
https://buildpacks.io/docs/reference/spec/migration/buildpack-api-0.6-0.7/
https://twitter.com/_sambhavkothari/status/1462855345919905797?s=20