Update yoast/phpunit-polyfills requirement from ^1.0 to ^2.0

Updates the requirements on [yoast/phpunit-polyfills](https://github.com/Yoast/PHPUnit-Polyfills) to permit the latest version.
- [Release notes](https://github.com/Yoast/PHPUnit-Polyfills/releases)
- [Changelog](https://github.com/Yoast/PHPUnit-Polyfills/blob/2.x/CHANGELOG.md)
- [Commits](Yoast/PHPUnit-Polyfills@1.0.0...2.0.0)

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

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

Author: dependabot[bot]

composer.json

@@ -39,7 +39,7 @@
 	"php-parallel-lint/php-parallel-lint": "^1.3",
 	"wp-cli/i18n-command": "^2.2",
 	"sebastian/phpcpd": "^3.0 || ^5.0 || ^6.0",
-	"yoast/phpunit-polyfills": "^1.0"
+	"yoast/phpunit-polyfills": "^2.0"
   },
   "prefer-stable" : true,
   "scripts": {