Bump orchestra/testbench from 4.18.0 to 6.24.1

Bumps [orchestra/testbench](https://github.com/orchestral/testbench) from 4.18.0 to 6.24.1.
- [Release notes](https://github.com/orchestral/testbench/releases)
- [Changelog](https://github.com/orchestral/testbench/blob/7.x/CHANGELOG-6.x.md)
- [Commits](orchestral/testbench@v4.18.0...v6.24.1)

---
updated-dependencies:
- dependency-name: orchestra/testbench
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

composer.json

@@ -25,7 +25,7 @@
         }
     },
     "require-dev": {
-        "orchestra/testbench": "~4.18.0",
+        "orchestra/testbench": "~6.24.1",
         "php-coveralls/php-coveralls": "^2.5.2"
     },
     "require": {