fix(CI): chagned the way R version is passed to the documentation wor…

…kflow

.github/workflows/common.yml

@@ -29,11 +29,7 @@ on:
   release:
     types: [published]
   schedule:
-    - cron: '21 13 * * 1,3,5'
-
-env:
-  # R version to use for the workflows
-  R_VERSION: "3.6"
+    - cron: "21 13 * * 1,3,5"
 
 # Docs on concurrency:
 # https://docs.github.com/en/actions/using-jobs/using-concurrency
@@ -56,7 +52,7 @@ jobs:
     uses: pharmaverse/admiralci/.github/workflows/pkgdown.yml@main
     if: github.event_name == 'push'
     with:
-      r-version: "$R_VERSION"
+      r-version: 3.6
       # Whether to skip multiversion docs
       # Note that if you have multiple versions of docs,
       # your URL links are likely to break due to path changes