[everything] bulk set event handler return types to void

ext/admin/main.php

@@ -39,7 +39,7 @@ class AdminPage extends Extension
     /** @var AdminPageTheme */
     protected Themelet $theme;
 
-    public function onPageRequest(PageRequestEvent $event)
+    public function onPageRequest(PageRequestEvent $event): void
     {
         global $database, $page, $user;
 
@@ -69,7 +69,7 @@ class AdminPage extends Extension
         }
     }
 
-    public function onCliGen(CliGenEvent $event)
+    public function onCliGen(CliGenEvent $event): void
     {
         $event->app->register('page:get')
             ->addArgument('query', InputArgument::REQUIRED)
@@ -155,12 +155,12 @@ class AdminPage extends Extension
             });
     }
 
-    public function onAdminBuilding(AdminBuildingEvent $event)
+    public function onAdminBuilding(AdminBuildingEvent $event): void
     {
         $this->theme->display_page();
     }
 
-    public function onPageSubNavBuilding(PageSubNavBuildingEvent $event)
+    public function onPageSubNavBuilding(PageSubNavBuildingEvent $event): void
     {
         global $user;
         if ($event->parent === "system") {
@@ -170,7 +170,7 @@ class AdminPage extends Extension
         }
     }
 
-    public function onUserBlockBuilding(UserBlockBuildingEvent $event)
+    public function onUserBlockBuilding(UserBlockBuildingEvent $event): void
     {
         global $user;
         if ($user->can(Permissions::MANAGE_ADMINTOOLS)) {