cran: Update lister implementation
The cran_info_db.rds
file we were using to get all CRAN package
versions is no longer updated since 2024-06-02 so the lister no
longer collected new package versions released since that date.
So update the lister implementation to use the METACRAN JSON database (around 260 Mb to download at time of writing) instead which is guaranteed to be up to date regarding new package releases on CRAN.
Related to #4711.
The CRAN loader also requires some updates, notably to fix some missing release dates and ensure proper ordering of releases.