add domain to allowed codeowner kinds

Signed-off-by: Andrew Thauer <athauer@wealthsimple.com>

.changeset/bright-spiders-sniff.md

@@ -2,4 +2,4 @@
 '@backstage/plugin-catalog-backend': patch
 ---
 
-Allow CodeOwnersProcessor to set spec.owner for System and Resource entity kinds.
+Allow CodeOwnersProcessor to set `spec.owner` for `System`, `Resource`, and `Domain` entity kinds.

plugins/catalog-backend/src/ingestion/processors/CodeOwnersProcessor.ts

@@ -29,7 +29,7 @@ import { filter, get, head, pipe, reverse } from 'lodash/fp';
 import { Logger } from 'winston';
 import { CatalogProcessor } from './types';
 
-const ALLOWED_KINDS = ['API', 'Component', 'Resource', 'System'];
+const ALLOWED_KINDS = ['API', 'Component', 'Domain', 'Resource', 'System'];
 
 const ALLOWED_LOCATION_TYPES = [
   'url',