Added index on [:target_id, :relationship_type] to :user_relationships (speeds up `Notification.exclude_blockers/_`).

priv/repo/migrations/20211229075801_user_relationships_target_id_relationship_type_index.exs

@@ -0,0 +1,9 @@
+defmodule Pleroma.Repo.Migrations.UserRelationshipsTargetIdRelationshipTypeIndex do
+  use Ecto.Migration
+
+  def change do
+    create_if_not_exists(
+      index(:user_relationships, [:target_id, :relationship_type])
+    )
+  end
+end