chore(deps): update dependency phpdocumentor/reflection-docblock to v6

Author: renovate-bot

Storage/composer.json

@@ -13,7 +13,7 @@
         "phpspec/prophecy-phpunit": "^2.0",
         "squizlabs/php_codesniffer": "2.*",
         "phpdocumentor/reflection": "^6.0",
-        "phpdocumentor/reflection-docblock": "^5.3.3",
+        "phpdocumentor/reflection-docblock": "^6.0.0",
         "erusev/parsedown": "^1.6",
         "phpseclib/phpseclib": "^2.0||^3.0",
         "google/cloud-pubsub": "^2.0",