Simplify ShowLive to avoid handle_params (#6059)

* Simplify ShowLive to avoid handle_params

* mix format

priv/templates/phx.gen.live/show.ex

@@ -27,13 +27,8 @@ defmodule <%= inspect context.web_module %>.<%= inspect Module.concat(schema.web
   end
 
   @impl true
-  def mount(_params, _session, socket) do
-    {:ok, socket}
-  end
-
-  @impl true
-  def handle_params(%{"id" => id}, _, socket) do
-    {:noreply,
+  def mount(%{"id" => id}, _session, socket) do
+    {:ok,
      socket
      |> assign(:page_title, "Show <%= schema.human_singular %>")
      |> assign(:<%= schema.singular %>, <%= inspect context.alias %>.get_<%= schema.singular %>!(id))}