Refactor to matching on filter list structure

lib/plausible/segments/segment.ex

@@ -197,15 +197,10 @@ defmodule Plausible.Segments.Segment do
   end
 
   defp dashboard_compatible_filter?(filter) do
-    regular_filter? =
-      is_list(filter) and length(filter) == 3 and
-        is_atom(Enum.at(filter, 0)) and
-        is_binary(Enum.at(filter, 1)) and
-        is_list(Enum.at(filter, 2))
-
-    has_not_done_filter? =
-      is_list(filter) and length(filter) == 2 and Enum.at(filter, 0) == :has_not_done
-
-    regular_filter? or has_not_done_filter?
+    case filter do
+      [operation, dimension, _clauses] when is_atom(operation) and is_binary(dimension) -> true
+      [:has_not_done, _] -> true
+      _ -> false
+    end
   end
 end