Schedule the CI

Often breaks due to external changes.

Author: nobu

.github/workflows/libyaml.yml

@@ -1,6 +1,11 @@
 name: libyaml
 
-on: [push, pull_request]
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron: '21 11 * * 0'
+  workflow_dispatch:
 
 jobs:
   ruby-versions:

.github/workflows/test.yml

@@ -1,6 +1,11 @@
 name: test
 
-on: [push, pull_request]
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron: '15 11 * * 0'
+  workflow_dispatch:
 
 env:
   JAVA_OPTS: '-Xms60M -Xmx1G'