build(deps-dev): bump yoast/phpunit-polyfills from 2.0.1 to 3.1.1

Bumps [yoast/phpunit-polyfills](https://github.com/Yoast/PHPUnit-Polyfills) from 2.0.1 to 3.1.1.
- [Release notes](https://github.com/Yoast/PHPUnit-Polyfills/releases)
- [Changelog](https://github.com/Yoast/PHPUnit-Polyfills/blob/3.x/CHANGELOG.md)
- [Commits](Yoast/PHPUnit-Polyfills@2.0.1...3.1.1)

---
updated-dependencies:
- dependency-name: yoast/phpunit-polyfills
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

composer.json

@@ -39,7 +39,7 @@
     "squizlabs/php_codesniffer": "^3.3",
     "wp-coding-standards/wpcs": "^3.1.0",
     "dealerdirect/phpcodesniffer-composer-installer": "^0.7.0",
-    "yoast/phpunit-polyfills": "^2.0",
+    "yoast/phpunit-polyfills": "^3.1",
     "phpstan/phpstan": "^1.10",
     "szepeviktor/phpstan-wordpress": "^1.3",
     "php-stubs/wp-cli-stubs": "^2.8"