build(deps-dev): update phpunit/phpunit requirement (#1830)

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/10.5.20/ChangeLog-10.5.md)
- [Commits](sebastianbergmann/phpunit@10.5.19...10.5.20)

---
updated-dependencies:
- dependency-name: phpunit/phpunit
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

composer.json

@@ -82,7 +82,7 @@
 		"fig-r/psr2r-sniffer": "2.1.0",
 		"overtrue/phplint": "9.1.2",
 		"phpstan/phpstan": "1.10.67",
-		"phpunit/phpunit": "10.5.19",
+		"phpunit/phpunit": "10.5.20",
 		"phpunit/php-code-coverage": "10.1.14",
 		"rector/rector": "0.15.13",
 		"squizlabs/php_codesniffer": "3.9.2"