The R package repository currently does not have support for older
versions of packages which should be stored in a separate /Archive
router. This PR remedies that by adding a new path router.
I am a member of a group that loves using Gitea and this bug has been
annoying us for a long time. Hope it can be merged in time for Gitea
1.23.0.
Any feedback much appreciated.
Fixes #32782
(cherry picked from commit 874b8484aa9f7e10172fd1a8a7c768e70b36c475)