Update orchestra/testbench requirement from ^3.9 to ^4.1

Updates the requirements on [orchestra/testbench](https://github.com/orchestral/testbench) to permit the latest version.
- [Release notes](https://github.com/orchestral/testbench/releases)
- [Changelog](https://github.com/orchestral/testbench/blob/4.x/CHANGELOG-4.x.md)
- [Commits](orchestral/testbench@v3.9.0...v4.1.0)

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

composer.json

@@ -25,7 +25,7 @@
         "laravel/nova": "^2.1",
         "mockery/mockery": "^1.0",
         "nunomaduro/collision": "^3.0",
-        "orchestra/testbench": "^3.9",
+        "orchestra/testbench": "^4.1",
         "php-coveralls/php-coveralls": "^2.1",
         "phpunit/phpunit": "^8.0",
         "symfony/thanks": "^1.0"