chore(core, llc): skip generating freezed map and when options (#2334)

Author: xsahil03x

packages/stream_chat/build.yaml

@@ -4,4 +4,8 @@ targets:
       json_serializable:
         options:
           explicit_to_json: true
-          field_rename: snake
+          field_rename: snake
+      freezed:
+        options:
+          map: false
+          when: false