Remove 'unlisted' handling for now.

It's just too slow (over 1 second on small systems, haven't looked at
the queries in detail yet). We'll need some other way to handle it.

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -233,7 +233,8 @@ def fetch_public_activities(opts \\ %{}) do
     q = fetch_activities_query(["https://www.w3.org/ns/activitystreams#Public"], opts)
 
     q
-    |> restrict_unlisted()
+    # Too slow
+    # |> restrict_unlisted()
     |> Repo.all()
     |> Enum.reverse()
   end

test/web/activity_pub/activity_pub_test.exs

@@ -171,6 +171,7 @@ test "doesn't return blocked activities" do
   end
 
   describe "public fetch activities" do
+    @tag :skip
     test "doesn't retrieve unlisted activities" do
       user = insert(:user)
       {:ok, unlisted_activity} = CommonAPI.post(user, %{"status" => "yeah", "visibility" => "unlisted"})