[RFE] Weekly package update automation: Generate package diff reports

[t-lo]

Current situation

Weekly package update automation currently does not generate a list of package changes. While helper scripts exist that create these package version diff lists, the scripts are not integrated with the github action that creates the weekly updates PR.

Impact

Manual boiler plating work is required each week to understand the actual changes introduced by the package updates PR.

Ideal future situation

The PR runs the necessary actions on GH self-hosted runners to generate the packages diff.

Implementation options

See manual scripts in https://github.com/flatcar/scripts/tree/krnowak/pkg-auto/pkg_auto .