make phpstan happy

Author: faissaloux

Diff for: phpstan.neon

@@ -5,3 +5,4 @@ parameters:
 
     ignoreErrors:
         - "#Undefined variable: \\$this#"
+        - "#Anonymous function should return Pest\\\\Expectation but returns Pest\\\\Mixins\\\\Expectation#"

Diff for: src/Autoload.php

@@ -4,6 +4,8 @@
 
 namespace Faissaloux\PestMath;
 
-expect()->extend('toBeDivisibleBy', function (int $divisor) {
+use Pest\Expectation;
+
+expect()->extend('toBeDivisibleBy', function (int $divisor): Expectation {
     return expect($this->value % $divisor === 0)->toBeTrue();
 });