Bump phpcompatibility/phpcompatibility-wp from 2.1.5 to 2.1.6

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] <[email protected]>

Author: dependabot[bot]

Diff for: composer.json

@@ -25,7 +25,7 @@
     "mikey179/vfsstream": "1.6.12",
     "mustache/mustache": "^2",
     "php-stubs/wordpress-stubs": "^6.0",
-    "phpcompatibility/phpcompatibility-wp": "2.1.5",
+    "phpcompatibility/phpcompatibility-wp": "2.1.6",
     "phpdocumentor/reflection": "^3.0",
     "phpstan/phpstan": "^1.0",
     "roave/security-advisories": "dev-latest",