chore(deps-dev): Update phpro/grumphp requirement from 1.1.* || 1.3.* || 1.4.* to 1.1.* || 1.3.* || 1.4.* || 1.13.*

Updates the requirements on phpro/grumphp to permit the latest version.

---
updated-dependencies:
- dependency-name: phpro/grumphp
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

composer.json

@@ -33,7 +33,7 @@
     "require-dev": {
         "friends-of-phpspec/phpspec-code-coverage": "^6",
         "php-parallel-lint/php-parallel-lint": "^1.3",
-        "phpro/grumphp": "1.1.* || 1.3.* || 1.4.*",
+        "phpro/grumphp": "1.1.* || 1.3.* || 1.4.* || 1.13.*",
         "phpspec/phpspec": "^7"
     },
     "scripts": {