only deploy when BUILD_PKGDOWN=true is set

Author: pat-s

.Rbuildignore

@@ -22,3 +22,4 @@
 ^revdep$
 ^clang-.*
 ^\.vscode$
+^gfortran.*

tic.R

@@ -5,7 +5,11 @@ get_stage("install") %>%
   add_step(step_install_cran("ranger")) %>%
   add_step(step_install_github("mlr-org/mlr3pkgdowntemplate"))
 
-do_pkgdown()
+if (ci_on_ghactions() && ci_has_env("BUILD_PKGDOWN")) {
+  # creates pkgdown site and pushes to gh-pages branch
+  # only for the runner with the "BUILD_PKGDOWN" env var set
+  do_pkgdown()
+}
 
 if (Sys.info()["sysname"] == "Linux") {
   do_readme_rmd()