Composer: raise minimum PHPCS version and update various version cons…

…traints

... after the tooling has also updated to the PHPCSStandards version of PHPCS.

Refs:
* https://github.com/PHPCSStandards/PHP_CodeSniffer/releases/tag/3.8.0
* https://github.com/PHPCSStandards/PHPCSUtils/releases
* https://github.com/PHPCSStandards/PHPCSExtra/releases

composer.json

@@ -29,9 +29,9 @@
 		"php-parallel-lint/php-console-highlighter": "^1.0.0",
 		"php-parallel-lint/php-parallel-lint": "^1.3.2",
 		"phpcompatibility/phpcompatibility-wp": "^2.1.4",
-		"phpcsstandards/phpcsextra": "^1.1.2",
-		"phpcsstandards/phpcsutils": "^1.0.8",
-		"squizlabs/php_codesniffer": "^3.7.2",
+		"phpcsstandards/phpcsextra": "^1.2.1",
+		"phpcsstandards/phpcsutils": "^1.0.9",
+		"squizlabs/php_codesniffer": "^3.8.0",
 		"wp-coding-standards/wpcs": "^3.0.1"
 	},
 	"require-dev": {