chore(deps-dev): Update drupol/php-conventions requirement

Updates the requirements on [drupol/php-conventions](https://github.com/drupol/php-conventions) to permit the latest version.
- [Release notes](https://github.com/drupol/php-conventions/releases)
- [Commits](drupol/php-conventions@2.0.3...3.0.0)

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

composer.json

@@ -22,7 +22,7 @@
         "symfony/psr-http-message-bridge": "^1 || ^2"
     },
     "require-dev": {
-        "drupol/php-conventions": "^2.0.3",
+        "drupol/php-conventions": "^3.0.0",
         "friends-of-phpspec/phpspec-code-coverage": "^5",
         "infection/infection": "^0.20.2",
         "infection/phpspec-adapter": "^0.1.1",