🧪🐛 Flip the conditional in PR sanity check

Author: webknjaz

.github/workflows/reusable-smoke-test.yml

@@ -36,7 +36,7 @@ jobs:
     - name: Fail on PRs against illegal branches
       if: >-
         github.event_name == 'pull_request'
-        && github.base_ref == github.event.repository.default_branch
+        && github.base_ref != github.event.repository.default_branch
       run: exit 1
 
   fail-fast: