chore(deps-dev): Bump yoast/phpunit-polyfills from 3.0.0 to 3.1.1

Bumps [yoast/phpunit-polyfills](https://github.com/Yoast/PHPUnit-Polyfills) from 3.0.0 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@3.0.0...3.1.1)

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

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

composer.json

@@ -5,7 +5,7 @@
         "phpcompatibility/phpcompatibility-wp": "2.1.6",
         "erusev/parsedown": "1.7.4",
         "dms/phpunit-arraysubset-asserts": "0.5.0",
-        "yoast/phpunit-polyfills": "3.0.0",
+        "yoast/phpunit-polyfills": "3.1.1",
         "johnpbloch/wordpress-core": "6.7.1",
         "wp-phpunit/wp-phpunit": "6.7.1",
         "wp-cli/wp-cli": "2.11.0"