CI: disable upgrade, run build once per week

Author: mtzguido

.github/workflows/linux-x64-upgrade.yaml

@@ -1,8 +1,10 @@
 name: Upgrade Everest
 on:
   workflow_dispatch:
-  schedule:
-    - cron: '1 4,10,16,22 * * *'
+  # This is disabled since ACL* is using a pinned F* version,
+  # and upgrades will almost surely fail.
+  # schedule:
+  #   - cron: '1 4,10,16,22 * * *'
 jobs:
   build:
     runs-on: [self-hosted, linux, X64]

.github/workflows/linux-x64.yaml

@@ -5,6 +5,8 @@ on:
     - _**
   pull_request:
   workflow_dispatch:
+  schedule:
+    - cron: '0 4 * * TUE' # every tuesday 4am
 jobs:
   build:
     runs-on: [self-hosted, linux, X64]