Improve Code Checker workflow (#66)

* Run workflow weekly

* Expect it to fail, silence failure

.github/workflows/code-checker.yml

@@ -5,16 +5,24 @@
 
 # See https://alfa.siteimprove.com/code-checker
 
+# Note that even if the code checker step by itself fails, the full workflow doesn't.
+# This reduces noise, and ensure that other problems in the workflow will still be reported.
+
 name: Accessibility Code Checker (this workflow *should* fail!)
 on:
   push:
     branches:
       - main
   workflow_dispatch:
+    schedule:
+      # Run weekly, on Monday morning at 05:00 UTC.
+      # Problems are reported to the latest editor of the script,
+      # currently https://github.com/Jym77
+      - cron: '0 5 * * 1'
 
 jobs:
   build:
-    name: Accessibility Code Checker (this workflow *should* fail!)
+    name: Accessibility Code Checker
     runs-on: ubuntu-latest
     strategy:
       matrix:
@@ -41,3 +49,6 @@ jobs:
         env:
           SI_USER_EMAIL: ${{ secrets.SI_USER_EMAIL }}
           SI_API_KEY: ${{ secrets.SI_API_KEY }}
+      - name: Expect failure of previous step
+        if: ${{ failure() }}
+        run: echo "Code Checker failed as expected"