only on mondays and remove ubuntu "devel"

Author: ThomasKnecht

.github/workflows/tic.yml

@@ -14,7 +14,7 @@ on:
   # for now, CRON jobs only run on the default branch of the repo (i.e. usually on master)
   schedule:
     # * is a special character in YAML so you have to quote this string
-    - cron: "0 4 * * *"
+    - cron: "0 4 * * 1"
 
 name: tic
 
@@ -31,7 +31,6 @@ jobs:
           # use a different tic template type if you do not want to build on all listed platforms
           - { os: windows-latest, r: "release" }
           - { os: macOS-latest, r: "release", pkgdown: "true", latex: "true" }
-          - { os: ubuntu-latest, r: "devel" }
           - { os: ubuntu-latest, r: "release" }
 
     env: