Replace the work around with the temporal mode latest for the retriev…

…al of the parameters for the locations.

api/routers/edr.py

@@ -53,10 +53,9 @@ async def get_locations(
         spatial_area=dstore.Polygon(
             points=[dstore.Point(lat=coord[1], lon=coord[0]) for coord in poly.exterior.coords],
         ),
-        temporal_interval=dstore.TimeInterval(start=start_datetime),  # HACK
+        temporal_mode="latest"
     )
 
-    # TODO: Add flag to protobuf so that it only retrieves the latest observations from the datastore.
     ts_response = await get_obs_request(ts_request)
 
     platform_parameters: DefaultDict[str, Set[str]] = defaultdict(set)