Allow recent versions of PHPBench

Author: greg0ire

composer.json

@@ -22,7 +22,7 @@
         "ext-phar":                  "*",
         "ext-pdo":                   "*",
         "doctrine/coding-standard":  "^6.0",
-        "phpbench/phpbench":         "^0.13",
+        "phpbench/phpbench":         "^0.13 || 1.0.0-alpha2",
         "phpstan/phpstan":           "^0.12",
         "phpstan/phpstan-phpunit":   "^0.12",
         "phpunit/phpunit":           "^7.0 || ^8.0 || ^9.0"