Add a weekly scheduled build to the CircleCI build

This should run at 03:00 every Sunday.

Author: floehopper

.circleci/config.yml

@@ -51,7 +51,7 @@ jobs:
 
 workflows:
   build-all:
-    jobs:
+    jobs: &all-jobs
       - build:
           matrix:
             parameters:
@@ -78,3 +78,12 @@ workflows:
               gemfile:
                 - gemfiles/Gemfile.minitest.latest
                 - gemfiles/Gemfile.test-unit.latest
+  weekly:
+    triggers:
+      - schedule:
+          cron: "0 3 * * 0"
+          filters:
+            branches:
+              only:
+                - main
+    jobs: *all-jobs