ci: Do not run dependabot on e2e test applications (#17813)

Not sure if this will also avoid these warnings from security alerts,
but it's worth a try.

Author: mydea

.github/dependabot.yml

@@ -22,3 +22,5 @@ updates:
       prefix: feat
       prefix-development: feat
       include: scope
+    exclude-paths:
+      - 'dev-packages/e2e-tests/test-applications/'