fix(ci): remove non-existent team from dependabot reviewers

Co-authored-by: hotlong <50353452+hotlong@users.noreply.github.com>

Author: Copilot

.github/dependabot.yml

@@ -15,8 +15,6 @@ updates:
       prefix: "chore"
       prefix-development: "chore"
       include: "scope"
-    reviewers:
-      - "objectstack-ai/maintainers"
     # Group all patch updates together
     groups:
       patch-updates: