chore: update gitignore list (#9437)

Updated the gitignore list with the command : `go run scripts/generate-gitignores.go`

options/gitignore/R

@@ -5,6 +5,9 @@
 # Session Data files
 .RData
 
+# User-specific files
+.Ruserdata
+
 # Example code in package build process
 *-Ex.R
 
@@ -25,12 +28,12 @@ vignettes/*.pdf
 .httr-oauth
 
 # knitr and R markdown default cache directories
-/*_cache/
+*_cache/
 /cache/
 
 # Temporary files created by R markdown
 *.utf8.md
 *.knit.md
 
-# Shiny token, see https://shiny.rstudio.com/articles/shinyapps.html
-rsconnect/
+# R Environment Variables
+.Renviron