Bump yoast/phpunit-polyfills from 3.1.2 to 4.0.0 (#1174)

Bumps [yoast/phpunit-polyfills](https://github.com/Yoast/PHPUnit-Polyfills) from 3.1.2 to 4.0.0.
- [Release notes](https://github.com/Yoast/PHPUnit-Polyfills/releases)
- [Changelog](https://github.com/Yoast/PHPUnit-Polyfills/blob/4.x/CHANGELOG.md)
- [Commits](Yoast/PHPUnit-Polyfills@3.1.2...4.0.0)

---
updated-dependencies:
- dependency-name: yoast/phpunit-polyfills
  dependency-version: 4.0.0
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

composer.json

@@ -27,7 +27,7 @@
 		"swissspidy/phpstan-no-private": "^0.2.0",
 		"szepeviktor/phpstan-wordpress": "^1.3.0",
 		"wp-coding-standards/wpcs": "^3.1.0",
-		"yoast/phpunit-polyfills": "^3.0.0"
+		"yoast/phpunit-polyfills": "^4.0.0"
 	},
 	"config": {
 		"allow-plugins": {