Automate updates of OS libraries

[NiccoloFei]

Certain extension, such as PostGIS and others, in order to function they require system libraries that should be packaged as part of the container image.
Given that, for such extensions we require keeping up-to-date both:

1. the extension(s) versions present in the container image, which we do via Renovate by using the Deb Datasource module to fetch PGDG package updates
2. the OS libraries that are packaged as part of the container image

Given that extensions are build on a push mechanism, e.g. only when a change is made to any file in an extension's directory, we need a way to:

1. verify if there are new updates for OS libraries
2. ideally keep track of what has been updated and for what distribution
3. trigger a new build containing the new updated OS libs

Versioning all the OS libraries individually via renovate would probably be too painful, given that in case of PostGIS (which to be fair should be the most extreme case) we'd be talking about versioning 80+ libraries.

Ideally this automation should also be generic, so that it can be reused (opt-in) by all the other extension's container images that require packaging OS libraries.