Make rocker builds not daily

Author: almahmoud

…ithub/workflows/daily-rocker-builds.yaml .github/workflows/rocker-builds.yaml.github/workflows/daily-rocker-builds.yaml renamed to .github/workflows/rocker-builds.yaml .github/workflows/daily-rocker-builds.yaml renamed to .github/workflows/rocker-builds.yaml

@@ -10,7 +10,7 @@ on:
       check-rocker-image:
         default: "rocker/rstudio"
   schedule:
-    - cron: '0 18 * * *'
+    - cron: '0 18 */4 * *'
 
 jobs:
   check_versions: