Update phpstan/phpstan-symfony requirement from 2.0.15 to 2.0.17 (#234)

Updates the requirements on [phpstan/phpstan-symfony](https://github.com/phpstan/phpstan-symfony) to permit the latest version.
- [Release notes](https://github.com/phpstan/phpstan-symfony/releases)
- [Commits](phpstan/phpstan-symfony@2.0.15...2.0.17)

---
updated-dependencies:
- dependency-name: phpstan/phpstan-symfony
  dependency-version: 2.0.17
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

composer.json

@@ -41,7 +41,7 @@
         "rector/rector": "2.4.2",
         "phpspec/prophecy-phpunit": "^2.0",
         "symfony/monolog-bundle": "*",
-        "phpstan/phpstan-symfony": "2.0.15"
+        "phpstan/phpstan-symfony": "2.0.17"
     },
     "minimum-stability": "stable",
     "suggest": {