Improve repology compatibility for wolfi package - Add url field to all package melange yaml file

[lioneloh]

Problematic :

Repology cannot scan and expose the wolfi distribution package because the URL field inside the APKIndex yaml file is missing.

Summary :

Repology is the API used by Renovate and other tools to detect and automate version bump. After this improvement, we could have wolfi distribution integrated to repology and then all apko for docker file could be scanned by Renovate to detect version bump of packages in a automated way.

Proposed changes :

Add the url field to all melange yaml files with the upstream url of the package. With this information filled the U field (URL field) inside APKIndex generated by melange should be populated ensuring repology compatibility.
It would be nice also to ensure that the url field is filled for all new package

Related issue : repology/repology-updater#1339