Composer: update PHPCS Composer plugin dependency

The DealerDirect Composer plugin has just released version `0.7.0`.

As Composer treats minors < 1.0 as majors, updating to this version requires an update to the `composer.json` requirements.

> For pre-1.0 versions it also acts with safety in mind and treats `^0.3` as `>=0.3.0 <0.4.0`.

Note:
This standard can be combined by end-users with other PHPCS standards which may also include the Dealerdirect Composer plugin. Also: projects which _require_ this standard, may also require the plugin directly.
With that in mind, it is strongly recommended to allow a wider range or versions to prevent conflicts, as per this PR.

Refs:
* https://github.com/Dealerdirect/phpcodesniffer-composer-installer/releases/tag/v0.7.0
* https://getcomposer.org/doc/articles/versions.md#caret-version-range-

composer.json

@@ -22,7 +22,7 @@
     ],
     "require": {
         "php": "^7.2 || ^8.0",
-        "dealerdirect/phpcodesniffer-composer-installer": "^0.6.2",
+        "dealerdirect/phpcodesniffer-composer-installer": "^0.6.2 || ^0.7",
         "slevomat/coding-standard": "^6.3.9",
         "squizlabs/php_codesniffer": "^3.5.5"
     },