PR #10758 made a slight change to find_versions_of_archive() which included
archive_url in the search process. While this fixed `spack create` and
`spack checksum` missing command-line arguments, it caused `spack
install` to prefer those URLs over those it found in the scrape process.
As a result, the package url was treated as a list_url causing all R
packages to stop fetching once the package was updated on CRAN.
This patch is more selective about including the archive_url in the
remote versions, explicitly overriding it with matching versions found
by the scraper.
6f1fe3904c