Update migrations

priv/repo/migrations/20250606103707_create_follows.exs

@@ -1,16 +0,0 @@
-defmodule Nulla.Repo.Migrations.CreateFollows do
-  use Ecto.Migration
-
-  def change do
-    create table(:follows, primary_key: false) do
-      add :id, :bigint, primary_key: true
-      add :user_id, references(:users, on_delete: :delete_all), null: false
-      add :target_id, references(:users, on_delete: :delete_all), null: false
-
-      timestamps()
-    end
-
-    create unique_index(:follows, [:user_id, :target_id])
-    create index(:follows, [:target_id])
-  end
-end