feat: have releaselist builder dump the urls json file used by scikit package

[sbillinge]

Problem

Scikit package can broadcast an issue to a database of software packages held in a json file with a specified name (I forget the name). So the user only has to maintain one database of software packages (in regolith as the canonical), when we run the builder, could we also do a json.dump of all the software packages found into a file with the correct name? User can then copy that to their login directory periodically to keep their broadcast json file up to date.

Proposed solution

implement the feature