Update orchestra/testbench requirement from ^5.0|^6.0 to ^6.23.0

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/6.x/CHANGELOG-6.x.md)
- [Commits](https://github.com/orchestral/testbench/commits/v6.23.0)

---
updated-dependencies:
- dependency-name: orchestra/testbench
  dependency-type: direct:development
...

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

Author: dependabot[bot]

composer.json

@@ -34,7 +34,7 @@
         "laravel/legacy-factories": "^1.1",
         "mockery/mockery": "^1.4",
         "orchestra/database": "^5.0|^6.0",
-        "orchestra/testbench": "^5.0|^6.0"
+        "orchestra/testbench": "^6.23.0"
     },
     "config": {
         "sort-packages": true