erase cran form lock file to ensure only rspm is used

[ci skip]

Author: lorenzwalthert

inst/update-renv-prepare.R

@@ -1,10 +1,4 @@
-# emulate renv::lockfile_read()$R$Repositories$RSPM, which is not available on previous version of renv
-
 options(
-  repos = c(RSPM = {
-    all_repos <- jsonlite::read_json("renv.lock")$R$Repositories
-    all_repos[sapply(all_repos, \(x) x$Name == "RSPM")][[1]]$URL
-  }), # CRAN is not an option, always use PPM
   install.packages.check.source = "no", # don't check if source packages are available
   install.packages.compile.from.source = "never" # probably redundant with the above 'no': If source package is available, only use source if no code needs to be compiled (needs compilation flag on CRAN).
 )

renv.lock

@@ -5,10 +5,6 @@
       {
         "Name": "RSPM",
         "URL": "https://packagemanager.posit.co/cran/2023-11-17"
-      },
-      {
-        "Name": "CRAN",
-        "URL": "https://cran.rstudio.com"
       }
     ]
   },