Update squizlabs/php_codesniffer requirement from ^3.7.2 to ^4.0.0

Updates the requirements on [squizlabs/php_codesniffer](https://github.com/PHPCSStandards/PHP_CodeSniffer) to permit the latest version.
- [Release notes](https://github.com/PHPCSStandards/PHP_CodeSniffer/releases)
- [Changelog](https://github.com/PHPCSStandards/PHP_CodeSniffer/blob/4.x/CHANGELOG-4.x.md)
- [Commits](PHPCSStandards/PHP_CodeSniffer@3.7.2...4.0.0)

---
updated-dependencies:
- dependency-name: squizlabs/php_codesniffer
  dependency-version: 4.0.0
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

composer.json

@@ -36,7 +36,7 @@
   "require-dev": {
     "brianium/paratest": "^7",
     "psalm/plugin-phpunit": "^0.19.5",
-    "squizlabs/php_codesniffer": "^3.7.2",
+    "squizlabs/php_codesniffer": "^4.0.0",
     "vimeo/psalm": "^6.10"
   },
   "conflict": {