try skipping vignette using RStan on GHA Windows runs

Author: jgabry

vignettes/visual-mcmc-diagnostics.Rmd

@@ -6,8 +6,8 @@ output:
   rmarkdown::html_vignette:
     toc: true
     toc_depth: 3
-params:
-  EVAL: !r identical(Sys.getenv("NOT_CRAN"), "true")
+params: 
+  EVAL: !r identical(Sys.getenv("NOT_CRAN"), "true") && !(isTRUE(as.logical(Sys.getenv("CI"))) && .Platform$OS.type == "windows")
 vignette: >
   %\VignetteIndexEntry{Visual MCMC diagnostics}
   %\VignetteEngine{knitr::rmarkdown}