Build(deps-dev): Bump ergebnis/test-util from 0.9.1 to 1.0.0

Bumps [ergebnis/test-util](https://github.com/ergebnis/test-util) from 0.9.1 to 1.0.0.
- [Release notes](https://github.com/ergebnis/test-util/releases)
- [Changelog](https://github.com/ergebnis/test-util/blob/master/CHANGELOG.md)
- [Commits](ergebnis/test-util@0.9.1...1.0.0)

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

composer.json

@@ -16,7 +16,7 @@
   "require-dev": {
     "doctrine/coding-standard": "^7.0.2",
     "ergebnis/composer-normalize": "^2.3.0",
-    "ergebnis/test-util": "^0.9.1",
+    "ergebnis/test-util": "^1.0.0",
     "infection/infection": "^0.15.3",
     "maglnet/composer-require-checker": "^2.1.0",
     "phpstan/extension-installer": "^1.0.3",