Update OT List (#888)

* Update OT List

Author: Brandr0id

origin-trials/downstream-trials.json

@@ -8,6 +8,14 @@
             "issue": "Acquisition Info",
             "flag": "msAcquisitionInfo"
         },
+        {
+            "label": "Ad Selection API",
+            "expiration": "2025-07-15",
+            "repo": "WICG/privacy-preserving-ads",
+            "explainer": "https://github.com/WICG/privacy-preserving-ads",
+            "issue": "Ad Selection API",
+            "flag": "AdSelectionAPI"
+        },
         {
             "label": "HTML+IDL `handwriting` attribute",
             "expiration": "2024-11-14",
@@ -34,4 +42,4 @@
         }
     ],
     "expired": []
-}
+}