Remove redundant ensure_scrubbed_html

It is never used as handling for fake and non-fake activities was merged
into one function above it

lib/pleroma/html.ex

@@ -71,14 +71,6 @@ defmodule Pleroma.HTML do
     end
   end
 
-  def ensure_scrubbed_html(
-        content,
-        scrubbers,
-        true = _fake
-      ) do
-    {:ignore, filter_tags(content, scrubbers)}
-  end
-
   defp generate_scrubber_signature(scrubber) when is_atom(scrubber) do
     generate_scrubber_signature([scrubber])
   end