chore(deps-dev): Bump phpcompatibility/phpcompatibility-wp

Bumps [phpcompatibility/phpcompatibility-wp](https://github.com/PHPCompatibility/PHPCompatibilityWP) from 2.1.5 to 2.1.6.
- [Release notes](https://github.com/PHPCompatibility/PHPCompatibilityWP/releases)
- [Commits](PHPCompatibility/PHPCompatibilityWP@2.1.5...2.1.6)

---
updated-dependencies:
- dependency-name: phpcompatibility/phpcompatibility-wp
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

composer.json

@@ -2,7 +2,7 @@
     "require-dev": {
         "phpunit/phpunit": "9.6.19",
         "automattic/vipwpcs": "3.0.1",
-        "phpcompatibility/phpcompatibility-wp": "2.1.5",
+        "phpcompatibility/phpcompatibility-wp": "2.1.6",
         "erusev/parsedown": "1.7.4",
         "dms/phpunit-arraysubset-asserts": "0.5.0",
         "yoast/phpunit-polyfills": "3.0.0",