Replace require_code_owner_reviews access with safe navigation operator

Author: Volodumur-Yatsenko

test/script_test.rb

@@ -0,0 +1,5 @@
+def test_approve_from_user
+  # ... other test code ...
+  assert_equal true, @obj.rules_required_pull_request_reviews('main')&.[]("require_code_owner_reviews")
+  # ... other test code ...
+end