The problem is that the version of nlme recorded in your project is not current: the current version of nlme available on CRAN is 3.1-142, whereas version 3.1-137 is recorded in your lockfile.
Because of that, renv instead attempts to download and install the source package. This fails because your machine does not have the requisite build tools (that is, Rtools: https://cran.r-project.org/bin/windows/Rtools/) installed (or it cannot find them).
I also note that you're using an older version of renv:
"renv": {
"Package": "renv",
"Version": "0.7.1-20",
"Source": "GitHub",
"RemoteType": "github",
"RemoteHost": "api.github.com",
"RemoteUsername": "rstudio",
"RemoteRepo": "renv",
"RemoteRef": "master",
"RemoteSha": "e8857e7d46ea4c2188169d908481808a4a3e4563",
"Hash": "3775ef1f40a06b4c0ecc5aa4aa9c9a28"
},
You might want to upgrade to the latest CRAN release, or the current development release.