Add invitation_id column to guest_invitations schema (#4811)

Co-authored-by: Adrian Gruntkowski <adrian.gruntkowski@gmail.com>

priv/repo/migrations/20241111121802_add_invitation_id_to_guest_invitations.exs

@@ -0,0 +1,14 @@
+defmodule Plausible.Repo.Migrations.AddInvitationIdToGuestInvitations do
+  use Ecto.Migration
+
+  @disable_ddl_transaction true
+  @disable_migration_lock true
+
+  def change do
+    alter table(:guest_invitations) do
+      add :invitation_id, :string
+    end
+
+    create unique_index(:guest_invitations, [:invitation_id])
+  end
+end