Make relatedResource IDs unique in mediaType test.

Author: BigBlueHat

tests/input/relatedResource/relatedResource-with-mediaType-ok.json

@@ -13,7 +13,7 @@
     "digestMultibase": "uZTQ0MjM1NiAgcmVwb3J0cy9yZWxhdGVkLXJlc291cmNlLmpzb24K",
     "mediaType": "application/json"
   },{
-    "id": "https://w3c.github.io/vc-data-model/related-resource.json",
+    "id": "https://w3c.github.io/vc-data-model/related-resource.json#",
     "digestSRI":
       "sha256-ca3d163bab055381827226140568f3bef7eaac187cebd76878e0b63e9e442356",
     "mediaType": "application/ld+json"