Framework: Upgrade from Laravel 9 to 10

Following Laravel guidance and GitHub diff.
Not yet in tested state with app-specific changes made.

tests/CreatesApplication.php

@@ -3,15 +3,14 @@
 namespace Tests;
 
 use Illuminate\Contracts\Console\Kernel;
+use Illuminate\Foundation\Application;
 
 trait CreatesApplication
 {
     /**
      * Creates the application.
-     *
-     * @return \Illuminate\Foundation\Application
      */
-    public function createApplication()
+    public function createApplication(): Application
     {
         $app = require __DIR__ . '/../bootstrap/app.php';
         $app->make(Kernel::class)->bootstrap();