Use new dependabot name in mergify conditions

Author: thomaseizinger

.mergify.yml

@@ -8,7 +8,7 @@ pull_request_rules:
       - "status-success=e2e_test"
       - "status-success=npm_build"
       - "status-success=license/cla"
-      - "author:dependabot-preview[bot]"
+      - "author:dependabot[bot]"
     actions:
       comment:
         message: "bors r+"
@@ -38,7 +38,7 @@ pull_request_rules:
       delete_head_branch:
   - name: nag if changelog is not updated
     conditions:
-      - "author!=dependabot-preview[bot]"
+      - "author!=dependabot[bot]"
       - "files!=create/CHANGELOG.md"
       - "files!=scripts/CHANGELOG.md"
       - review-requested!=''