Remove dead code: unused callbacks in :edit action

The on_save and on_close callbacks are never passed when editing
keychain credentials. Only credential_index uses :edit action, and
it does not provide these callbacks. Removed the unreachable code.

Author: elias-ba

lib/lightning_web/live/credential_live/keychain_credential_form_component.ex

@@ -124,24 +124,11 @@ defmodule LightningWeb.CredentialLive.KeychainCredentialFormComponent do
              socket.assigns.keychain_credential,
              params
            ) do
-        {:ok, keychain_credential} ->
-          socket =
-            socket
-            |> put_flash(:info, "Keychain credential updated successfully")
-            |> push_event("close_modal", %{id: socket.assigns.id})
-
+        {:ok, _keychain_credential} ->
           {:noreply,
-           then(socket, fn socket ->
-             if socket.assigns[:on_save] do
-               socket.assigns[:on_save].(keychain_credential)
-             end
-
-             if socket.assigns[:on_close] do
-               socket.assigns.on_close.()
-             end
-
-             socket
-           end)}
+           socket
+           |> put_flash(:info, "Keychain credential updated successfully")
+           |> push_event("close_modal", %{id: socket.assigns.id})}
 
         {:error, %Ecto.Changeset{} = changeset} ->
           {:noreply, assign(socket, :changeset, changeset)}