ci: tolerate protected Dependabot workflow updates

.github/workflows/dependabot-auto-merge.yml

@@ -182,7 +182,7 @@ jobs:
                   break;
                 } catch (error) {
                   lastError = error;
-                  if (error.status === 405 || error.status === 409) {
+                  if (error.status === 403 || error.status === 405 || error.status === 409) {
                     core.info("Cannot merge PR #" + pull_number + " with " + merge_method + ": " + error.message);
                     continue;
                   }