fixup! Update links.md

Signed-off-by: benjamin-j-powell <bjp@apple.com>

links.md

@@ -588,7 +588,7 @@ Relation links are used to add some context to certain events
   "link_kind": "ARTIFACT",
   "timestamp": "2023-03-20T14:27:05.315384Z",
   "source": {
-    "subject_id": "5668c352-dd9d-4dee-b334-384e4661d21b"
+    "context_id": "5668c352-dd9d-4dee-b334-384e4661d21b"
   },
   "target": {
     "context_id": "3579a5aa-ef46-4ee8-95db-0540298835de"
@@ -598,11 +598,6 @@ Relation links are used to add some context to certain events
   }
 }
 ```
-
-The `source` field allows for either providing the either the `subject_id` or
-the `context_id`. This allows for relation of different ID types provided by
-CDEvents while also being explicit in what the `id` is.
-
 ### Scalability
 
 Scalability is one of the bigger goals in this proposal and we wanted to ensure

schemas/links/embeddedlinkrelation.json

@@ -16,10 +16,6 @@
       "context_id": {
         "type": "string",
         "minLength": 1
-      },
-      "subject_id": {
-        "type": "string",
-        "minLength": 1
       }
     }
   },

schemas/links/linkrelation.json

@@ -22,10 +22,6 @@
     "description": "",
     "type": "object",
     "properties": {
-      "subject_id": {
-        "type": "string",
-        "minLength": 1
-      },
       "context_id": {
         "type": "string",
         "minLength": 1