[PHP]: Update symfony/phpunit-bridge requirement in /vendor-bin/phpunit

Updates the requirements on [symfony/phpunit-bridge](https://github.com/symfony/phpunit-bridge) to permit the latest version.
- [Release notes](https://github.com/symfony/phpunit-bridge/releases)
- [Changelog](https://github.com/symfony/phpunit-bridge/blob/6.3/CHANGELOG.md)
- [Commits](symfony/phpunit-bridge@v6.3.6...v6.3.8)

---
updated-dependencies:
- dependency-name: symfony/phpunit-bridge
  dependency-type: direct:development
...

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

vendor-bin/phpunit/composer.json

@@ -2,7 +2,7 @@
     "require-dev": {
         "dg/bypass-finals": "^1.5",
         "phpunit/phpunit": "9.6.13",
-        "symfony/phpunit-bridge": "6.3.6",
+        "symfony/phpunit-bridge": "6.3.8",
         "vimeo/psalm": "5.15.0",
         "psalm/plugin-phpunit": "0.18.4",
         "weirdan/doctrine-psalm-plugin": "2.9.0",