fix: resolve $this type in ->with(), dataset closures, and trait-bound test cases

[MrPunyapal]

Fixes two related gaps in $this type resolution inside Pest test closures.

$this in ->with() and dataset closures

Closures passed to ->with() or used as array-dataset values now resolve $this to the bound test case, so Laravel / PHPUnit helpers can be called without PHPStan reporting an undefined variable.

pest()->extend(TestCase::class)->in('Feature');

test('locale redirect', function (string $locale): void {
    $this->get(route('set-locale', $locale))->assertStatus(302);
})->with(function (): array {
    $this->from(route('posts.index')); // $this was previously undefined

    return ['en', 'fr'];
});

Trait methods on $this

When a trait is bound alongside a test case (or alone), PHPStan now recognizes methods, properties, and constants provided by that trait, instead of only looking at the class.

pest()->extend(TestCase::class);
pest()->use(Foo::class);

test('trait methods are visible on $this', function (): void {
    expect($this->foo())->toBeTrue(); // was: Call to undefined method Tests\TestCase::foo()
});

This works for pest()->extend(...)->use(...), split pest()->extend(...) / pest()->use(...) calls, file-level uses(Trait::class), and any combination of classes and traits.

Global Pest.php bindings

Bindings declared in Pest.php without ->in('...') are now applied to every test file, matching Pest runtime behavior.

// Pest.php
pest()->extend(TestCase::class);
pest()->use(Foo::class);

Closes pestphp/pest#1815 and pestphp/pest#1827