If you're using renv, then you should be able to make use of the global package cache to ensure that packages only ever need to be built the first time they're installed -- subsequent attempts to restore should then install the package from the global cache. Please see the documentation on caching here:
That said, this doesn't fill in the space for automatically pushing and building packages on Artifactory. This should be possible, but unfortunately neither renv nor Packrat provide the tooling necessary to streamline this process. However, if you point Packrat / renv at your Artifactory repository by setting the repos option as appropriate, Packrat and renv should download binaries if they be available.
Best,
Kevin