ci: add nightly CI configuration for version 13

This version will become LTS soon and therefore we enable a nightly CI run.

Author: alan-agius4

.circleci/config.yml

@@ -391,3 +391,25 @@ workflows:
             - build
             - test
             - e2e-cli
+
+  nightly:
+    triggers:
+      - schedule:
+          cron: '0 0 * * *'
+          filters:
+            branches:
+              only:
+                - 13.3.x
+    jobs:
+      # Linux jobs
+      - setup
+      - build:
+          requires:
+            - setup
+      - e2e-cli:
+          name: e2e-cli-nightly
+          requires:
+            - build
+      - test-browsers:
+          requires:
+            - build