fix: add SECRET_KEY_BASE for Rails 8 CI tests

Author: jaspermayone

.github/workflows/ci.yml

@@ -14,6 +14,7 @@ concurrency:
 env:
   RAILS_ENV: test
   CI: true
+  SECRET_KEY_BASE: test-secret-key-base-for-ci-environment-needs-to-be-long-enough
   ACTIVE_RECORD_ENCRYPTION_PRIMARY_KEY: test-primary-key-32-bytes-long!!
   ACTIVE_RECORD_ENCRYPTION_DETERMINISTIC_KEY: test-deterministic-key-32-bytes!
   ACTIVE_RECORD_ENCRYPTION_KEY_DERIVATION_SALT: test-salt-for-key-derivation