Fix missing wizard after loading CompilerExplorer without restart

Wizards should be reloaded after plugins are loaded. They might either
add wizard paths, or wizards that check for plugins might be loaded even
though they were not loaded before.
Emit PluginManager::pluginsChanged when plugins are loaded at runtime
too, and connect that to clearing the list of wizard factories.

Change-Id: I79e0fb4991074cba592296620f1758136d60b378
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/libs/extensionsystem/pluginmanager.cpp

@@ -1411,6 +1411,7 @@ void PluginManagerPrivate::loadPluginsAtRuntime(const QSet<PluginSpec *> &plugin
             spec->d->kill();
         }
     });
+    emit q->pluginsChanged();
 }
 
 /*!

src/plugins/coreplugin/iwizardfactory.cpp

@@ -431,6 +431,9 @@ void IWizardFactory::initialize()
     connect(resetAction, &QAction::triggered, &IWizardFactory::clearWizardFactories);
     connect(ICore::instance(), &ICore::newItemDialogStateChanged, resetAction,
             [resetAction] { resetAction->setEnabled(!ICore::isNewItemDialogRunning()); });
+    connect(ExtensionSystem::PluginManager::instance(),
+            &ExtensionSystem::PluginManager::pluginsChanged,
+            &IWizardFactory::clearWizardFactories);
 
     s_inspectWizardAction = new QAction(Tr::tr("Inspect Wizard State"), ActionManager::instance());
     ActionManager::registerAction(s_inspectWizardAction, "Wizard.Inspect");