composer(deps-dev): update phpunit/phpunit requirement

Updates the requirements on [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) to permit the latest version.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/master/ChangeLog-9.5.md)
- [Commits](sebastianbergmann/phpunit@9.5.2...9.5.3)

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

composer.json

@@ -32,7 +32,7 @@
         "jangregor/phpstan-prophecy": "^0.8.1",
         "phpspec/prophecy-phpunit": "^2.0",
         "phpstan/phpstan": "^0.12.80",
-        "phpunit/phpunit": "^9.5.2",
+        "phpunit/phpunit": "^9.5.3",
         "roave/security-advisories": "dev-master",
         "squizlabs/php_codesniffer": "^3.5"
     },