chore: migrate to PHP-CS-Fixer 3.x

.gitattributes

@@ -3,13 +3,11 @@
 /tests                   export-ignore
 /scripts                 export-ignore
 /.github                 export-ignore
-/.php_cs           export-ignore
+/.php-cs-fixer.dist.php  export-ignore
 .editorconfig            export-ignore
 .gitattributes           export-ignore
 .gitignore               export-ignore
-.travis.yml        export-ignore
 phpstan.neon             export-ignore
-rector.yaml        export-ignore
 phpunit.xml              export-ignore
 CHANGELOG.md             export-ignore
 CONTRIBUTING.md          export-ignore

.gitignore

@@ -4,7 +4,8 @@ composer.lock
 /vendor/
 coverage.xml
 .phpunit.result.cache
-.php_cs.cache
+/.php-cs-fixer.php
+.php-cs-fixer.cache
 .temp/coverage.php
 *.swp
 *.swo

.php-cs-fixer.dist.php

@@ -6,7 +6,7 @@ $finder = PhpCsFixer\Finder::create()
     ->in(__DIR__ . DIRECTORY_SEPARATOR . 'scripts')
     ->in(__DIR__ . DIRECTORY_SEPARATOR . 'stubs')
     ->in(__DIR__ . DIRECTORY_SEPARATOR . 'src')
-    ->append(['.php_cs']);
+    ->append(['.php-cs-fixer.dist.php']);
 
 $rules = [
     '@Symfony'               => true,
@@ -25,7 +25,7 @@ $rules = [
 
 $rules['increment_style'] = ['style' => 'post'];
 
-return PhpCsFixer\Config::create()
+return (new PhpCsFixer\Config())
     ->setUsingCache(true)
     ->setRules($rules)
     ->setFinder($finder);