Run the CI every day at 2am UTC

This should help to catch issues in newer versions
of distributions/packages.

.github/workflows/build-and-test.yml

@@ -1,6 +1,10 @@
 name: Build and run tests
 
-on: [pull_request, push]
+on:
+  push:
+  pull_request:
+  schedule:
+    - cron: '0 2 * * *'
 
 jobs:
   build: