chore: update PHP version to 8.1 and adjust dependencies

Author: Fluf22

clients/algoliasearch-client-php/.php-cs-fixer.dist.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+use PhpCsFixer\Config;
+use PhpCsFixer\Finder;
+use PhpCsFixer\Runner\Parallel\ParallelConfigFactory;
+
+return (new Config())
+    ->setParallelConfig(ParallelConfigFactory::detect())
+    ->setRiskyAllowed(true)
+    ->setRules([
+        '@PhpCsFixer' => true
+    ])
+    ->setUsingCache(false)
+    ->setFinder(
+        (new Finder())
+            ->in(__DIR__)
+    )
+;

clients/algoliasearch-client-php/composer.json

@@ -23,8 +23,8 @@
         "psr/simple-cache": "^1.0 || ^2.0 || ^3.0"
     },
     "require-dev": {
-        "friendsofphp/php-cs-fixer": "^3.80.0",
-        "phpunit/phpunit": "^11.0",
+        "friendsofphp/php-cs-fixer": "^3.91.3",
+        "phpunit/phpunit": "^10.0",
         "vlucas/phpdotenv": "^5.4",
         "phpstan/phpstan": "^1.12"
     },