Make user_id on asciicasts not-nullable

Author: ku1ik

priv/repo/migrations/20250209212642_make_asciiast_user_id_non_null.exs

@@ -0,0 +1,11 @@
+defmodule Asciinema.Repo.Migrations.MakeAsciiastUserIdNonNull do
+  use Ecto.Migration
+
+  def change do
+    alter table(:asciicasts) do
+      modify :user_id, references(:users), null: false
+    end
+
+    drop constraint(:asciicasts, "asciicasts_user_id_fk")
+  end
+end