[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/factories/UserFactory.php

@@ -15,7 +15,7 @@ class UserFactory extends Factory
      *
      * @return array<string, mixed>
      */
-    public function definition()
+    public function definition(): array
     {
         return [
             'name' => fake()->name(),
@@ -29,9 +29,9 @@ class UserFactory extends Factory
     /**
      * Indicate that the model's email address should be unverified.
      *
-     * @return static
+     * @return $this
      */
-    public function unverified()
+    public function unverified(): static
     {
         return $this->state(fn (array $attributes) => [
             'email_verified_at' => null,