firefox: remove some more unnecessary fields from search.json

hosts/common/programs/firefox/default.nix

@@ -49,6 +49,7 @@ let
 
     extraPolicies = {
       # firefox policy schema is documented in <repo:mozilla-firefox/firefox:browser/components/enterprisepolicies/schemas/policies-schema.json>
+      # and <https://mozilla.github.io/policy-templates>
       # however the bulk of them seem to not actually have any effect T_T
       #
       # XXX(2024-12-02): using `nixExtensions` causes `about:debugging` to be blocked.

hosts/common/programs/firefox/search.json

@@ -28,13 +28,6 @@
     }
   ],
   "metaData": {
-    "locale": "en-US",
-    "region": "unknown",
-    "channel": "default",
-    "experiment": "",
-    "distroID": "nixos",
-    "appDefaultEngineId": "google",
-    "useSavedOrder": true,
     "defaultEngineId": "search@kagi.comdefault",
     "defaultEngineIdHash": "hrzTeftqb+2F9OI3GYJwG6XAMryJr8Eut/3f90YKv3k="
   }