Fix invalid key in Dependabot config

Author: myabc

.github/dependabot.yml

@@ -39,7 +39,7 @@ updates:
         patterns:
           - "aws-*"
     ignore:
-      - dependency_name: "openproject-octicons"
+      - dependency-name: "openproject-octicons"
       - dependency-name: "openproject-octicons_helper"
       - dependency-name: "openproject-primer_view_components"
   - package-ecosystem: "github-actions"