composer(deps-dev): update symfony/var-dumper requirement

Updates the requirements on [symfony/var-dumper](https://github.com/symfony/var-dumper) to permit the latest version.
- [Release notes](https://github.com/symfony/var-dumper/releases)
- [Changelog](https://github.com/symfony/var-dumper/blob/7.1/CHANGELOG.md)
- [Commits](symfony/var-dumper@v5.4.0...v7.1.3)

---
updated-dependencies:
- dependency-name: symfony/var-dumper
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

composer.json

@@ -31,7 +31,7 @@
     "require-dev": {
         "bamarni/composer-bin-plugin": "^1.8",
         "phpunit/phpunit": "^9.6",
-        "symfony/var-dumper": "^5.4"
+        "symfony/var-dumper": "^7.1"
     },
     "config": {
         "allow-plugins": {