Drop obsolete pixelfed workaround

This pixelfed issue was fixed in 2022-12 in
https://github.com/pixelfed/pixelfed/pull/3932

Co-authored-by: FloatingGhost <hannah@coffee-and-dreams.uk>

lib/pleroma/object/fetcher.ex

@@ -348,10 +348,6 @@ defmodule Pleroma.Object.Fetcher do
         {"ld+json", %{"profile" => "https://www.w3.org/ns/activitystreams"}} ->
           {:ok, final_id, body}
 
-        # pixelfed sometimes (and only sometimes) responds with http instead of https
-        {"ld+json", %{"profile" => "http://www.w3.org/ns/activitystreams"}} ->
-          {:ok, final_id, body}
-
         _ ->
           {:error, {:content_type, content_type}}
       end

test/pleroma/object/fetcher_test.exs

@@ -773,23 +773,6 @@ defmodule Pleroma.Object.FetcherTest do
       end)
 
       assert {:ok, _, "{}"} = Fetcher.get_object("https://mastodon.social/2")
-
-      Tesla.Mock.mock(fn
-        %{
-          method: :get,
-          url: "https://mastodon.social/2"
-        } ->
-          %Tesla.Env{
-            status: 200,
-            headers: [
-              {"content-type",
-               "application/ld+json; profile=\"http://www.w3.org/ns/activitystreams\""}
-            ],
-            body: "{}"
-          }
-      end)
-
-      assert {:ok, _, "{}"} = Fetcher.get_object("https://mastodon.social/2")
     end
 
     test "should not return ok with other content types" do