Issue #2001310 by chx, effulgentsia, Berdir, YesCT: Disallow firing hooks during update.

core/includes/update.inc

core/lib/Drupal/Core/Cache/DatabaseBackend.php

core/lib/Drupal/Core/DependencyInjection/UpdateBundle.php

core/lib/Drupal/Core/Extension/UpdateModuleHandler.php

core/lib/Drupal/Core/Routing/RouteBuilderStatic.php

core/modules/block/block.install

core/modules/language/language.install

core/modules/node/node.install

core/modules/system/system.install

core/modules/toolbar/toolbar.install

core/modules/user/user.install

core/modules/views/views.install

core/update.php