Update phpunit/phpunit requirement from 7.4.* || 8.3.* || 8.4.* to 7.4.* || 8.3.* || 8.4.* || 8.5.*

Updates the requirements on [phpunit/phpunit](https://github.com/sebastianbergmann/phpunit) to permit the latest version.
- [Release notes](https://github.com/sebastianbergmann/phpunit/releases)
- [Changelog](https://github.com/sebastianbergmann/phpunit/blob/master/ChangeLog-8.5.md)
- [Commits](https://github.com/sebastianbergmann/phpunit/commits/8.5.0)

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

Author: dependabot-preview[bot]

composer.json

@@ -32,7 +32,7 @@
         "consistence/coding-standard": "3.7",
         "orchestra/testbench": "~3.0 || 4.*",
         "phpmd/phpmd": "^2.6",
-        "phpunit/phpunit": "7.4.* || 8.3.* || 8.4.*",
+        "phpunit/phpunit": "7.4.* || 8.3.* || 8.4.* || 8.5.*",
         "slevomat/coding-standard": "4.8.7",
         "squizlabs/php_codesniffer": "^3.4"
     },