fix regex and typo

Signed-off-by: pitwegner <pit.wegner@student.hpi.de>

.changeset/stale-files-sniff.md

@@ -2,4 +2,4 @@
 '@backstage/catalog-model': minor
 ---
 
-Modified the regex for dns label validation to support IDN domains
+Modified the regex for DNS label validation to support IDN domains

packages/catalog-model/src/validation/CommonValidatorFunctions.ts

@@ -91,7 +91,7 @@ export class CommonValidatorFunctions {
       typeof value === 'string' &&
       value.length >= 1 &&
       value.length <= 63 &&
-      /^((?!\-))(xn\-\-)?[a-z0-9\-]+[a-z0-9]$/.test(value)
+      /^((?!\-))(xn\-\-)?[a-z0-9\-]*[a-z0-9]$/.test(value)
     );
   }