Monitor storage-access-headers repo from Privacy CG (#1495)

Close #1494.

src/data/monitor.json

@@ -347,6 +347,10 @@
     "immersive-web/body-tracking": {
       "lastreviewed": "2024-09-01",
       "comment": "no published content yet"
+    },
+    "privacycg/storage-access-headers": {
+      "comment": "spec is empty",
+      "lastreviewed": "2024-09-09"
     }
   },
   "specs": {
@@ -407,4 +411,4 @@
       "comment": "no longer worked on and implementation status is unclear"
     }
   }
-}
+}