[10.x] Uses PHP Native Type Declarations 🐘 (#6010)

* Adds basic typing around method's arguments and return types

* Adds missing `closure` type

* Adds typing on tests

* Fixes `RedirectIfAuthenticated`

* Fixes `Authenticate`

* Improves `RedirectIfAuthenticated` types

* Fixes user factory `unverified` return type

database/seeders/DatabaseSeeder.php

@@ -9,10 +9,8 @@ class DatabaseSeeder extends Seeder
 {
     /**
      * Seed the application's database.
-     *
-     * @return void
      */
-    public function run()
+    public function run(): void
     {
         // \App\Models\User::factory(10)->create();